Python and lyrics of Zemfira’s new album: capturing the spirit of her songs

Estimated read time – 15 min

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Zemfira’s latest studio album, Borderline, was released in February, 8 years after the previous one. For this album, various people cooperated with her, including her relatives – the riff for the song “Таблетки” was written by her nephew from London. The album turned out to be diverse: for instance, the song “Остин” is dedicated to the main character of the Homescapes game by the Russian studio Playrix (by the way, check out the latest Business Secrets with the Bukhman brothers, they also mention it there). Zemfira liked the game a lot, thus, she contacted Playrix to create this song. Also, the song “Крым” was written as a soundtrack to a new film by Zemfira’s colleague Renata Litvinova.

Listen new album in Apple Music / Яндекс.Музыке / Spotify

Nevertheless, the spirit of the whole album is rather gloomy – the songs often repeat the words ‘боль’, ‘ад’, ‘бесишь’ and other synonyms. We decided to conduct an exploratory analysis of her album, and then, using the Word2Vec model and a cosine measure, look at the semantic closeness of the songs and calculate the general mood of the album.

For those who are bored with reading about data preparation and analysis steps, you can go directly to the results.

Data preparation

For starters, we write a data processing script. The purpose of the script is to collect a united csv-table from a set of text files, each of which contains a song. At the same time, we have to get rid of all punctuation marks and unnecessary words as we need to focus only on significant content.

import pandas as pd
import re
import string
import pymorphy2
from nltk.corpus import stopwords

Then we create a morphological analyzer and expand the list of everything that needs to be discarded:

morph = pymorphy2.MorphAnalyzer()
stopwords_list = stopwords.words('russian')
stopwords_list.extend(['куплет', 'это', 'я', 'мы', 'ты', 'припев', 'аутро', 'предприпев', 'lyrics', '1', '2', '3', 'то'])
string.punctuation += '—'

The names of the songs are given in English, so we have to create a dictionary for translation into Russian and a dictionary, from which we will later make a table:

result_dict = dict()

songs_dict = {
    'snow':'снег идёт',
    'crimea':'крым',
    'mother':'мама',
    'ostin':'остин',
    'abuse':'абьюз',
    'wait_for_me':'жди меня',
    'tom':'том',
    'come_on':'камон',
    'coat':'пальто',
    'this_summer':'этим летом',
    'ok':'ок',
    'pills':'таблетки'
}

Let’s define several necessary functions. The first one reads the entire song from the file and removes line breaks, the second clears the text from unnecessary characters and words, and the third one converts the words to normal form, using the pymorphy2 morphological analyzer. The pymorphy2 module does not always handle ambiguity well – additional processing is required for the words ‘ад’ and ‘рай’.

def read_song(filename):
    f = open(f'{filename}.txt', 'r').read()
    f = f.replace('\n', ' ')
    return f

def clean_string(text):
    text = re.split(' |:|\.|\(|\)|,|"|;|/|\n|\t|-|\?|\[|\]|!', text)
    text = ' '.join([word for word in text if word not in string.punctuation])
    text = text.lower()
    text = ' '.join([word for word in text.split() if word not in stopwords_list])
    return text

def string_to_normal_form(string):
    string_lst = string.split()
    for i in range(len(string_lst)):
        string_lst[i] = morph.parse(string_lst[i])[0].normal_form
        if (string_lst[i] == 'аду'):
            string_lst[i] = 'ад'
        if (string_lst[i] == 'рая'):
            string_lst[i] = 'рай'
    string = ' '.join(string_lst)
    return string

After all this preparation, we can get back to the data and process each song and read the file with the corresponding name:

name_list = []
text_list = []
for song, name in songs_dict.items():
    text = string_to_normal_form(clean_string(read_song(song)))
    name_list.append(name)
    text_list.append(text)

Then we combine everything into a DataFrame and save it as a csv-file.

df = pd.DataFrame()
df['name'] = name_list
df['text'] = text_list
df['time'] = [290, 220, 187, 270, 330, 196, 207, 188, 269, 189, 245, 244]
df.to_csv('borderline.csv', index=False)

Result:
2-table.png

Word cloud for the whole album

To begin with the analysis, we have to construct a word cloud, because it can display the most common words found in these songs. We import the required libraries, read the csv-file and set the configurations:

import nltk
from wordcloud import WordCloud
import pandas as pd
import matplotlib.pyplot as plt
from nltk import word_tokenize, ngrams

%matplotlib inline
nltk.download('punkt')
df = pd.read_csv('borderline.csv')

Now we create a new figure, set the design parameters and, using the word cloud library, display words with the size directly proportional to the frequency of the word. We additionally indicate the name of the song above the corresponding graph.

fig = plt.figure()
fig.patch.set_facecolor('white')
plt.subplots_adjust(wspace=0.3, hspace=0.2)
i = 1
for name, text in zip(df.name, df.text):
    tokens = word_tokenize(text)
    text_raw = " ".join(tokens)
    wordcloud = WordCloud(colormap='PuBu', background_color='white', contour_width=10).generate(text_raw)
    plt.subplot(4, 3, i, label=name,frame_on=True)
    plt.tick_params(labelsize=10)
    plt.imshow(wordcloud)
    plt.axis("off")
    plt.title(name,fontdict={'fontsize':7,'color':'grey'},y=0.93)
    plt.tick_params(labelsize=10)
    i += 1

3-wordcloud.jpg

EDA of the lyrics

Let us move to the next part and analyze the lyrics. To do this, we have to import special libraries to deal with data and visualization:

import plotly.graph_objects as go
import plotly.figure_factory as ff
from scipy import spatial
import collections
import pymorphy2
import gensim

morph = pymorphy2.MorphAnalyzer()

Firstly, we should count the overall number of words in each song, the number of unique words, and their percentage:

songs = []
total = []
uniq = []
percent = []

for song, text in zip(df.name, df.text):
    songs.append(song)
    total.append(len(text.split()))
    uniq.append(len(set(text.split())))
    percent.append(round(len(set(text.split())) / len(text.split()), 2) * 100)

All this information should be written in a DataFrame and additionally we want to count the number of words per minute for each song:

df_words = pd.DataFrame()
df_words['song'] = songs
df_words['total words'] = total
df_words['uniq words'] = uniq
df_words['percent'] = percent
df_words['time'] = df['time']
df_words['words per minute'] = round(total / (df['time'] // 60))
df_words = df_words[::-1]

4-table.png

It would be great to visualize the data, so let us build two bar charts: one for the number of words in the song, and the other one for the number of words per minute.

colors_1 = ['rgba(101,181,205,255)'] * 12
colors_2 = ['rgba(62,142,231,255)'] * 12

fig = go.Figure(data=[
    go.Bar(name='📝 Total number of words,
           text=df_words['total words'],
           textposition='auto',
           x=df_words.song,
           y=df_words['total words'],
           marker_color=colors_1,
           marker=dict(line=dict(width=0)),),
    go.Bar(name='🌀 Unique words',
           text=df_words['uniq words'].astype(str) + '<br>'+ df_words.percent.astype(int).astype(str) + '%' ,
           textposition='inside',
           x=df_words.song,
           y=df_words['uniq words'],
           textfont_color='white',
           marker_color=colors_2,
           marker=dict(line=dict(width=0)),),
])

fig.update_layout(barmode='group')

fig.update_layout(
    title = 
        {'text':'<b>The ratio of the number of unique words to the total</b><br><span style="color:#666666"></span>'},
    showlegend = True,
    height=650,
    font={
        'family':'Open Sans, light',
        'color':'black',
        'size':14
    },
    plot_bgcolor='rgba(0,0,0,0)',
)
fig.update_layout(legend=dict(
    yanchor="top",
    xanchor="right",
))

fig.show()
colors_1 = ['rgba(101,181,205,255)'] * 12
colors_2 = ['rgba(238,85,59,255)'] * 12

fig = go.Figure(data=[
    go.Bar(name='⏱️ Track length, min.',
           text=round(df_words['time'] / 60, 1),
           textposition='auto',
           x=df_words.song,
           y=-df_words['time'] // 60,
           marker_color=colors_1,
           marker=dict(line=dict(width=0)),
          ),
    go.Bar(name='🔄 Words per minute',
           text=df_words['words per minute'],
           textposition='auto',
           x=df_words.song,
           y=df_words['words per minute'],
           marker_color=colors_2,
           textfont_color='white',
           marker=dict(line=dict(width=0)),
          ),
])

fig.update_layout(barmode='overlay')

fig.update_layout(
    title = 
        {'text':'<b>Track length and words per minute</b><br><span style="color:#666666"></span>'},
    showlegend = True,
    height=650,
    font={
        'family':'Open Sans, light',
        'color':'black',
        'size':14
    },
    plot_bgcolor='rgba(0,0,0,0)'
)


fig.show()

Working with Word2Vec model

Using the gensim module, load the model pointing to a binary file:

model = gensim.models.KeyedVectors.load_word2vec_format('model.bin', binary=True)

Для материала мы использовали готовую обученную на Национальном Корпусе Русского Языка модель от сообщества RusVectōrēs

The Word2Vec model is based on neural networks and allows you to represent words in the form of vectors, taking into account the semantic component. It means that if we take two words – for instance, “mom” and “dad”, then represent them as two vectors and calculate the cosine, the values ​​will be close to 1. Similarly, two words that have nothing in common in their meaning have a cosine measure close to 0.

Now we will define the get_vector function: it will take a list of words, recognize a part of speech for each word, and then receive and summarize vectors, so that we can find vectors even for whole sentences and texts.

def get_vector(word_list):
    vector = 0
    for word in word_list:
        pos = morph.parse(word)[0].tag.POS
        if pos == 'INFN':
            pos = 'VERB'
        if pos in ['ADJF', 'PRCL', 'ADVB', 'NPRO']:
            pos = 'NOUN'
        if word and pos:
            try:
                word_pos = word + '_' + pos
                this_vector = model.word_vec(word_pos)
                vector += this_vector
            except KeyError:
                continue
    return vector

For each song, find a vector and select the corresponding column in the DataFrame:

vec_list = []
for word in df['text']:
    vec_list.append(get_vector(word.split()))
df['vector'] = vec_list

So, now we should compare these vectors with one another, calculating their cosine proximity. Those songs with a cosine metric higher than 0.5 will be saved separately – this way we will get the closest pairs of songs. We will write the information about the comparison of vectors into the two-dimensional list result.

similar = dict()
result = []
for song_1, vector_1 in zip(df.name, df.vector):
    sub_list = []
    for song_2, vector_2 in zip(df.name.iloc[::-1], df.vector.iloc[::-1]):
        res = 1 - spatial.distance.cosine(vector_1, vector_2)
        if res > 0.5 and song_1 != song_2 and (song_1 + ' / ' + song_2 not in similar.keys() and song_2 + ' / ' + song_1 not in similar.keys()):
            similar[song_1 + ' / ' + song_2] = round(res, 2)
        sub_list.append(round(res, 2))
    result.append(sub_list)

Moreover, we can construct the same bar chart:

df_top_sim = pd.DataFrame()
df_top_sim['name'] = list(similar.keys())
df_top_sim['value'] = list(similar.values())
df_top_sim.sort_values(by='value', ascending=False)

И построим такой же bar chart:

colors = ['rgba(101,181,205,255)'] * 5

fig = go.Figure([go.Bar(x=df_top_sim['name'],
                        y=df_top_sim['value'],
                        marker_color=colors,
                        width=[0.4,0.4,0.4,0.4,0.4],
                        text=df_top_sim['value'],
                        textfont_color='white',
                        textposition='auto')])

fig.update_layout(
    title = 
        {'text':'<b>Топ-5 closest songs</b><br><span style="color:#666666"></span>'},
    showlegend = False,
    height=650,
    font={
        'family':'Open Sans, light',
        'color':'black',
        'size':14
    },
    plot_bgcolor='rgba(0,0,0,0)',
    xaxis={'categoryorder':'total descending'}
)

fig.show()

Given the vector of each song, let us calculate the vector of the entire album – add the vectors of the songs. Then, for such a vector, using the model, we get the words that are the closest in spirit and meaning.

def get_word_from_tlist(lst):
    for word in lst:
        word = word[0].split('_')[0]
        print(word, end=' ')

vec_sum = 0
for vec in df.vector:
    vec_sum += vec
sim_word = model.similar_by_vector(vec_sum)
get_word_from_tlist(sim_word)

небо тоска тьма пламень плакать горе печаль сердце солнце мрак

This is probably the key result and the description of Zemfira’s album in just 10 words.

Finally, we build a general heat map, each cell of which is the result of comparing the texts of two tracks with a cosine measure.

colorscale=[[0.0, "rgba(255,255,255,255)"],
            [0.1, "rgba(229,232,237,255)"],
            [0.2, "rgba(216,222,232,255)"],
            [0.3, "rgba(205,214,228,255)"],
            [0.4, "rgba(182,195,218,255)"],
            [0.5, "rgba(159,178,209,255)"],
            [0.6, "rgba(137,161,200,255)"],
            [0.7, "rgba(107,137,188,255)"],
            [0.8, "rgba(96,129,184,255)"],
            [1.0, "rgba(76,114,176,255)"]]

font_colors = ['black']
x = list(df.name.iloc[::-1])
y = list(df.name)
fig = ff.create_annotated_heatmap(result, x=x, y=y, colorscale=colorscale, font_colors=font_colors)
fig.show()

Results and data interpretation

To give valuable conclusions, we would like to take another look at everything we got. First of all, let us focus on the word cloud. It is easy to see that the words ‘боль’, ‘невозможно’, ‘сорваться’, ‘растерзаны’, ‘сложно’, ‘терпеть’, ‘любить’ have a very decent size, because such words are often found throughout the entire lyrics:

Давайте ещё раз посмотрим на всё, что у нас получилось — начнём с облака слов. Нетрудно заметить, что у слов «боль», «невозможно», «сорваться», «растерзаны», «сложно», «терпеть», «любить» размер весьма приличный — всё потому, что такие слова встречаются часто на протяжении всего текста песен:

9-wordcloud.jpg

The song “Крым” turned out to be one of the most diverse songs – it contains 74% of unique words. Also, the song “Снег идет” contains very few words, so the majority, which is 82%, are unique. The largest song on the album in terms of amount of words is the track “Таблетки” – there are about 150 words in total.

As it was shown on the last chart, the most dynamic track is “Таблетки”, as much as 37 words per minute – nearly one word for every two seconds – and the longest track is “Абьюз”, and according to the previous chart, it also has the lowest percentage of unique words – 46%.

Top 5 most semantically similar text pairs:

We also got the vector of the entire album and found the closest words. Just take a look at them – ‘тьма’, ‘тоска’, ‘плакать’, ‘горе’, ‘печаль’, ‘сердце’ – this is the list of words that characterizes Zemfira’s lyrics!

небо тоска тьма пламень плакать горе печаль сердце солнце мрак

The final result is a heat map. From the visualization, it is noticeable that almost all songs are quite similar to each other – the cosine measure for many pairs exceeds the value of 0.4.

Conclusions

In the material, we carried out an EDA of the entire text of the new album and, using the pre-trained Word2Vec model, we proved the hypothesis – most of the “Borderline” songs are permeated with rather dark lyrics. However, this is normal, because we love Zemfira precisely for her sincerity and straightforwardness.

 No comments    62   1 mon   analysis   Analytics engineering   data analytics   plotly   python

Data normalization with SQL

Estimated read time – 5 min

According to GIGO (garbage in, garbage out) principle, errors in input data lead to erroneous analysis results. The results of our work directly depend on the quality of data preparation.

For instance, when we need to prepare data to use in ML algorithms (like k-NN, k-means, logistic regression, etc.), features in the original dataset may vary in scale like the age and height of a person. This may lead to the incorrect performance of the algorithm. Thus, such data needs to be rescaled first.

In this tutorial, we will consider the ways to scale the data using SQL query: min-max normalization, min-max normalization for an arbitrary range, and z-score normalization. For each of these methods we have prepared two SQL query options: one using a SELECT subquery and another using a window function OVER().

We will work with the simple table students that contains the data on the height of the students:

name height
Ivan 174
Peter 181
Dan 199
Kate 158
Mike 179
Silvia 165
Giulia 152
Robert 188
Steven 177
Sophia 165

Min-max rescaling

Min-max scaling approach scales the data using the fixed range from 0 to 1. In this case, all the data is on the same scale which will exclude the impact of outliers on the conclusions.

The formula for the min-max scaling is given as:

We multiply the numerator by 1.0 in order to get a floating point number at the end.

SQL-query with a subquery:

SELECT height, 
       1.0 * (height-t1.min_height)/(t1.max_height - t1.min_height) AS scaled_minmax
  FROM students, 
      (SELECT min(height) as min_height, 
              max(height) as max_height 
         FROM students
      ) as t1;

SQL-query with a window function:

SELECT height, 
       (height - MIN(height) OVER ()) * 1.0 / (MAX(height) OVER () - MIN(height) OVER ()) AS scaled_minmax
  FROM students;

As a result, we get the values in [0, 1] range where 0 is the height of the shortest student and 1 is the height of the tallest one.

name height scaled_minmax
Ivan 174 0.46809
Peter 181 0.61702
Dan 199 1
Kate 158 0.12766
Mike 179 0.57447
Silvia 165 0.2766
Giulia 152 0
Robert 188 0.76596
Steven 177 0.53191
Sophia 165 0.2766

Rescaling within a given range

This is an option of min-max normalization between an arbitrary set of values. When it comes to data scaling, the values do not always need to be in the range between 0 and 1. In these cases, the following formula is applied.

This allows us to scale the data to an arbitrary scale. In our example, let’s assume a=10.0 and b=20.0.

SQL-query with subquery:

SELECT height, 
       ((height - min_height) * (20.0 - 10.0) / (max_height - min_height)) + 10 AS scaled_ab
  FROM students,
      (SELECT MAX(height) as max_height, 
              MIN(height) as min_height
         FROM students  
      ) t1;

SQL-query with a window function:

SELECT height, 
       ((height - MIN(height) OVER() ) * (20.0 - 10.0) / (MAX(height) OVER() - MIN(height) OVER())) + 10.0 AS scaled_ab
  FROM students;

We receive similar results as before, but with data spread between 10 and 20.

name height scaled_ab
Ivan 174 14.68085
Peter 181 16.17021
Dan 199 20
Kate 158 11.2766
Mike 179 15.74468
Silvia 165 12.76596
Giulia 152 10
Robert 188 17.65957
Steven 177 15.31915
Sophia 165 12.76596

Z-score normalization

Using Z-score normalization, the data will be scaled so that it has the properties of a standard normal distribution where the mean (μ) is equal to 0 and the standard deviation (σ) to 1.

Z-score is calculated using the formula:

SQL-query with a subquery:

SELECT height, 
       (height - t1.mean) * 1.0 / t1.sigma AS zscore
  FROM students,
      (SELECT AVG(height) AS mean, 
              STDDEV(height) AS sigma
         FROM students
        ) t1;

SQL-query with a window function:

SELECT height, 
       (height - AVG(height) OVER()) * 1.0 / STDDEV(height) OVER() AS z-score
  FROM students;

As a result, we can easily notice the outliers that exceed the standard deviation.

name height zscore
Ivan 174 0.01488
Peter 181 0.53582
Dan 199 1.87538
Kate 158 -1.17583
Mike 179 0.38698
Silvia 165 -0.65489
Giulia 152 -1.62235
Robert 188 1.05676
Steven 177 0.23814
Sophia 165 -0.65489
 No comments    181   5 mon   Analytics engineering   sql

How to build Animated Charts like Hans Rosling in Plotly

Estimated read time – 11 min

Hans Rosling’s work on world countries economic growth presented in 2007 at TEDTalks can be attributed to one of the most iconic data visualizations, ever created. Just check out this video, in case you don’t know what we’re talking about:

Sometimes we want to compare standards of living in other countries. One way to do this is to refer to the Big Mac index, which the Economist magazine has kept track of since 1986. The key idea this index represents is to measure purchasing power parity (PPP) in different countries, considering costs of domestic production. To make a standard burger, one would need the following ingredients: cheese, meat, bread and vegetables. Considering that all these ingredients can be produced locally, we can compare the production cost of one Big Mac in different countries, and measure purchasing power. Plus, McDonald’s is the world’s most popular franchise network, its restaurants are almost everywhere around the globe.

In today’s material, we will build a Motion Chart for the Big Mac index using Plotly. Following Hann Rosling’s idea, the chart will display country population along the X-axis and GDP per capita in US dollars along the Y. The size of the dots is going to be proportional to the Big Mac Index for a given country. And the color of the dots will represent the continent where the country is located.

Preparing Data

Even though The Economist has been updating it for over 30 years and sharing its observations publicly, the dataset contains many missing values. It also lacks continents names, but we can handle it by supplementing the data with some more datasets that can be found in our repo.

Let’s start by importing the libraries:

import pandas as pd
from pandas.errors import ParserError
import plotly.graph_objects as go
import numpy as np
import requests
import io

We can access the dataset directly from GitHub. Just use the following function to send a GET request to a CSV file and create a Pandas DataFrame. However, in some cases, this may raise a  ParseError because of the caption title, so we will add a try block:

def read_raw_file(link):
    raw_csv = requests.get(link).content
    try:
        df = pd.read_csv(io.StringIO(raw_csv.decode('utf-8')))
    except ParserError:
        df = pd.read_csv(io.StringIO(raw_csv.decode('utf-8')), skiprows=3)
    return df

bigmac_df = read_raw_file('https://github.com/valiotti/leftjoin/raw/master/motion-chart-big-mac/big-mac.csv')
population_df = read_raw_file('https://github.com/valiotti/leftjoin/raw/master/motion-chart-big-mac/population.csv')
dgp_df = read_raw_file('https://github.com/valiotti/leftjoin/raw/master/motion-chart-big-mac/gdp.csv')
continents_df = read_raw_file('https://github.com/valiotti/leftjoin/raw/master/motion-chart-big-mac/continents.csv')

From The Economist dataset we will need these columns: country name, local price, dollar exchange rate, country code (iso_a3) and record date. Take the timeline from 2005 to 2020, as the records are most complete for this span. And divide the local price by the exchange rate to calculate the price of one Big Mac in US dollars.

bigmac_df = bigmac_df[['name', 'local_price', 'dollar_ex', 'iso_a3', 'date']]
bigmac_df = bigmac_df[bigmac_df['date'] >= '2005-01-01']
bigmac_df = bigmac_df[bigmac_df['date'] < '2020-01-01']
bigmac_df['date'] = pd.DatetimeIndex(bigmac_df['date']).year
bigmac_df = bigmac_df.drop_duplicates(['date', 'name'])
bigmac_df = bigmac_df.reset_index(drop=True)
bigmac_df['dollar_price'] = bigmac_df['local_price'] / bigmac_df['dollar_ex']

Take a look at the result:

1_1.png

Next, let’s try adding a new column called continents. To ease the task, leave only two columns containing country code and continent name. Then we need to iterate through the bigmac_df[‘iso_a3’] column, adding a continent name for the corresponding values. However some cases may raise an error, because it’s not really clear, whether a country belongs to Europe or Asia, we will consider such cases as Europe by default.

continents_df = continents_df[['Continent_Name', 'Three_Letter_Country_Code']]
continents_list = []
for country in bigmac_df['iso_a3']:
    try:
        continents_list.append(continents_df.loc[continents_df['Three_Letter_Country_Code'] == country]['Continent_Name'].item())
    except ValueError:
        continents_list.append('Europe')
bigmac_df['continent'] = continents_list

Now we can drop unnecessary columns, apply sorting by country names and date, convert values in the date column into integers, and view the current result:

bigmac_df = bigmac_df.drop(['local_price', 'iso_a3', 'dollar_ex'], axis=1)
bigmac_df = bigmac_df.sort_values(by=['name', 'date'])
bigmac_df['date'] = bigmac_df['date'].astype(int)

2-20.png

Then we need to fill up missing values for The Big Mac index with zeros and remove the Republic of China, since this partially recognized state is not included in the World Bank datasets. The UAE occurs several times, this can lead to issues.

countries_list = list(bigmac_df['name'].unique())
years_set = {i for i in range(2005, 2020)}
for country in countries_list:
    if len(bigmac_df[bigmac_df['name'] == country]) < 15:
        this_continent = bigmac_df[bigmac_df['name'] == country].continent.iloc[0]
        years_of_country = set(bigmac_df[bigmac_df['name'] == country]['date'])
        diff = years_set - years_of_country
        dict_to_df = pd.DataFrame({
                      'name':[country] * len(diff),
                      'date':list(diff),
                      'dollar_price':[0] * len(diff),
                      'continent': [this_continent] * len(diff)
                     })
        bigmac_df = bigmac_df.append(dict_to_df)
bigmac_df = bigmac_df[bigmac_df['name'] != 'Taiwan']
bigmac_df = bigmac_df[bigmac_df['name'] != 'United Arab Emirates']

Next, let’s augment the data with GDP per capita and population from other datasets. Both datasets have differences in country names, so we need to specify such cases explicitly and replace them.

years = [str(i) for i in range(2005, 2020)]

countries_replace_dict = {
    'Russian Federation': 'Russia',
    'Egypt, Arab Rep.': 'Egypt',
    'Hong Kong SAR, China': 'Hong Kong',
    'United Kingdom': 'Britain',
    'Korea, Rep.': 'South Korea',
    'United Arab Emirates': 'UAE',
    'Venezuela, RB': 'Venezuela'
}
for key, value in countries_replace_dict.items():
    population_df['Country Name'] = population_df['Country Name'].replace(key, value)
    gdp_df['Country Name'] = gdp_df['Country Name'].replace(key, value)

Finally, extract population data and GDP for the given years, adding the data to the bigmac_df DataFrame:

countries_list = list(bigmac_df['name'].unique())

population_list = []
gdp_list = []
for country in countries_list:
    population_for_country_df = population_df[population_df['Country Name'] == country][years]
    population_list.extend(list(population_for_country_df.values[0]))
    gdp_for_country_df = gdp_df[gdp_df['Country Name'] == country][years]
    gdp_list.extend(list(gdp_for_country_df.values[0]))
    
bigmac_df['population'] = population_list
bigmac_df['gdp'] = gdp_list
bigmac_df['gdp_per_capita'] = bigmac_df['gdp'] / bigmac_df['population']

And here is our final dataset:

3-16.png

Creating a chart in Plotly

The population in China or India, on average, is 10 times more than in other countries. That’s why we need to transform X-axis to Log Scale, to make the chart easier for interpreting. The log-transformation is a common way to address skewness in data.

fig_dict = {
    "data": [],
    "layout": {},
    "frames": []
}

fig_dict["layout"]["xaxis"] = {"title": "Population", "type": "log"}
fig_dict["layout"]["yaxis"] = {"title": "GDP per capita (in $)", "range":[-10000, 120000]}
fig_dict["layout"]["hovermode"] = "closest"
fig_dict["layout"]["updatemenus"] = [
    {
        "buttons": [
            {
                "args": [None, {"frame": {"duration": 500, "redraw": False},
                                "fromcurrent": True, "transition": {"duration": 300,
                                                                    "easing": "quadratic-in-out"}}],
                "label": "Play",
                "method": "animate"
            },
            {
                "args": [[None], {"frame": {"duration": 0, "redraw": False},
                                  "mode": "immediate",
                                  "transition": {"duration": 0}}],
                "label": "Pause",
                "method": "animate"
            }
        ],
        "direction": "left",
        "pad": {"r": 10, "t": 87},
        "showactive": False,
        "type": "buttons",
        "x": 0.1,
        "xanchor": "right",
        "y": 0,
        "yanchor": "top"
    }
]

We will also add a slider to filter data within a certain range:

sliders_dict = {
    "active": 0,
    "yanchor": "top",
    "xanchor": "left",
    "currentvalue": {
        "font": {"size": 20},
        "prefix": "Year: ",
        "visible": True,
        "xanchor": "right"
    },
    "transition": {"duration": 300, "easing": "cubic-in-out"},
    "pad": {"b": 10, "t": 50},
    "len": 0.9,
    "x": 0.1,
    "y": 0,
    "steps": []
}

By default, the chart will display data for 2005 before we click on the “Play” button.

continents_list_from_df = list(bigmac_df['continent'].unique())
year = 2005
for continent in continents_list_from_df:
    dataset_by_year = bigmac_df[bigmac_df["date"] == year]
    dataset_by_year_and_cont = dataset_by_year[dataset_by_year["continent"] == continent]
    
    data_dict = {
        "x": dataset_by_year_and_cont["population"],
        "y": dataset_by_year_and_cont["gdp_per_capita"],
        "mode": "markers",
        "text": dataset_by_year_and_cont["name"],
        "marker": {
            "sizemode": "area",
            "sizeref": 200000,
            "size":  np.array(dataset_by_year_and_cont["dollar_price"]) * 20000000
        },
        "name": continent,
        "customdata": np.array(dataset_by_year_and_cont["dollar_price"]).round(1),
        "hovertemplate": '<b>%{text}</b>' + '<br>' +
                         'GDP per capita: %{y}' + '<br>' +
                         'Population: %{x}' + '<br>' +
                         'Big Mac price: %{customdata}$' +
                         '<extra></extra>'
    }
    fig_dict["data"].append(data_dict)

Next, we need to fill up the frames field, which will be used for animating the data. Each frame represents a certain data point from 2005 to 2019.

for year in years:
    frame = {"data": [], "name": str(year)}
    for continent in continents_list_from_df:
        dataset_by_year = bigmac_df[bigmac_df["date"] == int(year)]
        dataset_by_year_and_cont = dataset_by_year[dataset_by_year["continent"] == continent]

        data_dict = {
            "x": list(dataset_by_year_and_cont["population"]),
            "y": list(dataset_by_year_and_cont["gdp_per_capita"]),
            "mode": "markers",
            "text": list(dataset_by_year_and_cont["name"]),
            "marker": {
                "sizemode": "area",
                "sizeref": 200000,
                "size": np.array(dataset_by_year_and_cont["dollar_price"]) * 20000000
            },
            "name": continent,
            "customdata": np.array(dataset_by_year_and_cont["dollar_price"]).round(1),
            "hovertemplate": '<b>%{text}</b>' + '<br>' +
                             'GDP per capita: %{y}' + '<br>' +
                             'Population: %{x}' + '<br>' +
                             'Big Mac price: %{customdata}$' +
                             '<extra></extra>'
        }
        frame["data"].append(data_dict)

    fig_dict["frames"].append(frame)
    slider_step = {"args": [
        [year],
        {"frame": {"duration": 300, "redraw": False},
         "mode": "immediate",
         "transition": {"duration": 300}}
    ],
        "label": year,
        "method": "animate"}
    sliders_dict["steps"].append(slider_step)

Just a few finishing touches left, instantiate the chart, set colors, fonts and title.

fig_dict["layout"]["sliders"] = [sliders_dict]

fig = go.Figure(fig_dict)

fig.update_layout(
    title = 
        {'text':'<b>Motion chart</b><br><span style="color:#666666">The Big Mac index from 2005 to 2019</span>'},
    font={
        'family':'Open Sans, light',
        'color':'black',
        'size':14
    },
    plot_bgcolor='rgba(0,0,0,0)'
)
fig.update_yaxes(nticks=4)
fig.update_xaxes(tickfont=dict(family='Open Sans, light', color='black', size=12), nticks=4, gridcolor='lightgray', gridwidth=0.5)
fig.update_yaxes(tickfont=dict(family='Open Sans, light', color='black', size=12), nticks=4, gridcolor='lightgray', gridwidth=0.5)

fig.show()

Bingo! The Motion Chart is done:

View the code on GitHub

 No comments    324   11 mon   data analytics   Data engineering   plotly

Collecting Social Media Data for Top ML, AI & Data Science related accounts on Instagram

Estimated read time – 9 min

Instagram is in the top 5 most visited websites, perhaps not for our industry. Nevertheless, we are going to test this hypothesis using Python and our data analytics skills. In this post, we will share how to collect social media data using the Instagram API.

Data collection method
The Instagram API won’t let us collect data about other platform users for no reason, but there is always a way. Try sending the following request:

https://instagram.com/leftjoin/?__a=1

The request returns a JSON object with detailed user information, for instance, we can easily get an account name, number of posts, followers, subscriptions, as well as the first ten user posts with likes count, comments and etc. The pyInstagram library allows sending such requests.

SQL schema
Data will be collected into thee Clickhouse tables: users, posts, comments. The users table will contain user data, such as user id, username, user’s first and last name, account description, number of followers, subscriptions, posts, comments, and likes, whether an account is verified or not, and so on.

CREATE TABLE instagram.users
(
    `added_at` DateTime,
    `user_id` UInt64,
    `user_name` String,
    `full_name` String,
    `base_url` String,
    `biography` String,
    `followers_count` UInt64,
    `follows_count` UInt64,
    `media_count` UInt64,
    `total_comments` UInt64,
    `total_likes` UInt64,
    `is_verified` UInt8,
    `country_block` UInt8,
    `profile_pic_url` Nullable(String),
    `profile_pic_url_hd` Nullable(String),
    `fb_page` Nullable(String)
)
ENGINE = ReplacingMergeTree
ORDER BY added_at

The posts table will be populated with the post owner name, post id, caption, comments coun, and so on. To check whether a post is an advertisement, Instagram carousel, or a video we can use these fields: is_ad, is_album and is_video.

CREATE TABLE instagram.posts
(
    `added_at` DateTime,
    `owner` String,
    `post_id` UInt64,
    `caption` Nullable(String),
    `code` String,
    `comments_count` UInt64,
    `comments_disabled` UInt8,
    `created_at` DateTime,
    `display_url` String,
    `is_ad` UInt8,
    `is_album` UInt8,
    `is_video` UInt8,
    `likes_count` UInt64,
    `location` Nullable(String),
    `recources` Array(String),
    `video_url` Nullable(String)
)
ENGINE = ReplacingMergeTree
ORDER BY added_at

In the comments table, we store each comment separately with the comment owner and text.

CREATE TABLE instagram.comments
(
    `added_at` DateTime,
    `comment_id` UInt64,
    `post_id` UInt64,
    `comment_owner` String,
    `comment_text` String
)
ENGINE = ReplacingMergeTree
ORDER BY added_at

Writing the script
Import the following classes from the library: Account, Media, WebAgent and Comment.

from instagram import Account, Media, WebAgent, Comment
from datetime import datetime
from clickhouse_driver import Client
import requests
import pandas as pd

Next, create an instance of the WebAgent class required for some library methods and data updating. To collect any meaningful information we need to have at least account names. Since we don’t have them yet, send the following request to search for porifles by the  keywords specified in queries_list. The search results will be composed of Instagram pages that match any keyword in the list.

agent = WebAgent()
queries_list = ['machine learning', 'data science', 'data analytics', 'analytics', 'business intelligence',
                'data engineering', 'computer science', 'big data', 'artificial intelligence',
                'deep learning', 'data scientist','machine learning engineer', 'data engineer']
client = Client(host='12.34.56.789', user='default', password='', port='9000', database='instagram')
url = 'https://www.instagram.com/web/search/topsearch/?context=user&count=0'

Let’s iterate the keywords collecting all matching accounts. Then remove duplicates from the obtained list by converting it to set and back.

response_list = []
for query in queries_list:
    response = requests.get(url, params={
        'query': query
    }).json()
    response_list.extend(response['users'])
instagram_pages_list = []
for item in response_list:
    instagram_pages_list.append(item['user']['username'])
instagram_pages_list = list(set(instagram_pages_list))

Now we need to loop through the list of pages and request detailed information about an account if it’s not in the table yet. Create an instance of the Account class and pass username as a parameter.
Then update the account information using the agent.update()
method. We will collect only the first 100 posts to keep it moving. Next, create a list named media_list to store received post ids after calling the agent.get_media() method.


Collecting user media data

all_posts_list = []
username_count = 0
for username in instagram_pages_list:
    if client.execute(f"SELECT count(1) FROM users WHERE user_name='{username}'")[0][0] == 0:
        print('username:', username_count, '/', len(instagram_pages_list))
        username_count += 1
        account_total_likes = 0
        account_total_comments = 0
        try:
            account = Account(username)
        except Exception as E:
            print(E)
            continue
        try:
            agent.update(account)
        except Exception as E:
            print(E)
            continue
        if account.media_count < 100:
            post_count = account.media_count
        else:
            post_count = 100
        print(account, post_count)
        media_list, _ = agent.get_media(account, count=post_count, delay=1)
        count = 0

Because we need to count the total number of likes and comments before adding a new user to our database, we’ll start with them first. Almost all required fields belong to the Media class:


Collecting user posts

for media_code in media_list:
            if client.execute(f"SELECT count(1) FROM posts WHERE code='{media_code}'")[0][0] == 0:
                print('posts:', count, '/', len(media_list))
                count += 1

                post_insert_list = []
                post = Media(media_code)
                agent.update(post)
                post_insert_list.append(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
                post_insert_list.append(str(post.owner))
                post_insert_list.append(post.id)
                if post.caption is not None:
                    post_insert_list.append(post.caption.replace("'","").replace('"', ''))
                else:
                    post_insert_list.append("")
                post_insert_list.append(post.code)
                post_insert_list.append(post.comments_count)
                post_insert_list.append(int(post.comments_disabled))
                post_insert_list.append(datetime.fromtimestamp(post.date).strftime('%Y-%m-%d %H:%M:%S'))
                post_insert_list.append(post.display_url)
                try:
                    post_insert_list.append(int(post.is_ad))
                except TypeError:
                    post_insert_list.append('cast(Null as Nullable(UInt8))')
                post_insert_list.append(int(post.is_album))
                post_insert_list.append(int(post.is_video))
                post_insert_list.append(post.likes_count)
                if post.location is not None:
                    post_insert_list.append(post.location)
                else:
                    post_insert_list.append('')
                post_insert_list.append(post.resources)
                if post.video_url is not None:
                    post_insert_list.append(post.video_url)
                else:
                    post_insert_list.append('')
                account_total_likes += post.likes_count
                account_total_comments += post.comments_count
                try:
                    client.execute(f'''
                        INSERT INTO posts VALUES {tuple(post_insert_list)}
                    ''')
                except Exception as E:
                    print('posts:')
                    print(E)
                    print(post_insert_list)

Store comments in the variable with the same name after calling the get_comments() method:


Collecting post comments

comments = agent.get_comments(media=post)
                for comment_id in comments[0]:
                    comment_insert_list = []
                    comment = Comment(comment_id)
                    comment_insert_list.append(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
                    comment_insert_list.append(comment.id)
                    comment_insert_list.append(post.id)
                    comment_insert_list.append(str(comment.owner))
                    comment_insert_list.append(comment.text.replace("'","").replace('"', ''))
                    try:
                        client.execute(f'''
                            INSERT INTO comments VALUES {tuple(comment_insert_list)}
                        ''')
                    except Exception as E:
                        print('comments:')
                        print(E)
                        print(comment_insert_list)

And now, when we have obtained user posts and comments new information can be added to the table.


Collecting user data

user_insert_list = []
        user_insert_list.append(datetime.now().strftime('%Y-%m-%d %H:%M:%S'))
        user_insert_list.append(account.id)
        user_insert_list.append(account.username)
        user_insert_list.append(account.full_name)
        user_insert_list.append(account.base_url)
        user_insert_list.append(account.biography)
        user_insert_list.append(account.followers_count)
        user_insert_list.append(account.follows_count)
        user_insert_list.append(account.media_count)
        user_insert_list.append(account_total_comments)
        user_insert_list.append(account_total_likes)
        user_insert_list.append(int(account.is_verified))
        user_insert_list.append(int(account.country_block))
        user_insert_list.append(account.profile_pic_url)
        user_insert_list.append(account.profile_pic_url_hd)
        if account.fb_page is not None:
            user_insert_list.append(account.fb_page)
        else:
            user_insert_list.append('')
        try:
            client.execute(f'''
                INSERT INTO users VALUES {tuple(user_insert_list)}
            ''')
        except Exception as E:
            print('users:')
            print(E)
            print(user_insert_list)

Conclusion
To sum up, we have collected data of 500 users, with nearly 20K posts and 40K comments. As the database will be updated, we can write a simple query to get the top 10 ML, AI & Data Science related most followed accounts for today.

SELECT *
FROM users
ORDER BY followers_count DESC
LIMIT 10

And as a bonus, here is a list of the most interesting Instagram accounts on this topic:

  1. @ai_machine_learning
  2. @neuralnine
  3. @datascienceinfo
  4. @compscistuff
  5. @computersciencelife
  6. @welcome.ai
  7. @papa_programmer
  8. @data_science_learn
  9. @neuralnet.ai
  10. @techno_thinkers

View the code on GitHub

 No comments    252   1 y   Analytics engineering   clickhouse   data analytics   instagram   python

Analyzing Business Intelligence (BI) and Analytics job market in Tableau

Estimated read time – 13 min

1.1.png

According to the SimilarWeb rating, hh.ru is the third among the most popular job search websites in the world. In one of the conversations with Roman Bunin, we came up with the idea of making a common project and collect data using the HeadHunter API for later analysis and visualization in Tableau Public. Our goal was to understand the dependency between salary and skills specified in a job posting and compare how things are in Moscow, Saint Petersburg, and other regions.

Data Collection Process

Our scheme is based on fetching a  brief job description, returned by the GET /vacancies method. According to the structure we need to create the following columns: vacancy type, id, vacancy rate (‘premium’), pre-employment testing (‘has_test’), company address, salary, work schedule, and so forth. We created a table using the following CREATE query down below:


Query for creating the vacancies_short table in ClickHouse

CREATE TABLE headhunter.vacancies_short
(
    `added_at` DateTime,
    `query_string` String,
    `type` String,
    `level` String,
    `direction` String,
    `vacancy_id` UInt64,
    `premium` UInt8,
    `has_test` UInt8,
    `response_url` String,
    `address_city` String,
    `address_street` String,
    `address_building` String,
    `address_description` String,
    `address_lat` String,
    `address_lng` String,
    `address_raw` String,
    `address_metro_stations` String,
    `alternate_url` String,
    `apply_alternate_url` String,
    `department_id` String,
    `department_name` String,
    `salary_from` Nullable(Float64),
    `salary_to` Nullable(Float64),
    `salary_currency` String,
    `salary_gross` Nullable(UInt8),
    `name` String,
    `insider_interview_id` Nullable(UInt64),
    `insider_interview_url` String,
    `area_url` String,
    `area_id` UInt64,
    `area_name` String,
    `url` String,
    `published_at` DateTime,
    `employer_url` String,
    `employer_alternate_url` String,
    `employer_logo_urls_90` String,
    `employer_logo_urls_240` String,
    `employer_logo_urls_original` String,
    `employer_name` String,
    `employer_id` UInt64,
    `response_letter_required` UInt8,
    `type_id` String,
    `type_name` String,
    `archived` UInt8,
    `schedule_id` Nullable(String)
)
ENGINE = ReplacingMergeTree
ORDER BY vacancy_id

The first script collects data from the HeadHunter website through API and inserts to our Database using the following libraries:

import requests
from clickhouse_driver import Client
from datetime import datetime
import pandas as pd
import re

Next, we create a DataFrame and connect to the Database in ClickHouse:

queries = pd.read_csv('hh_data.csv')
client = Client(host='1.234.567.890', user='default', password='', port='9000', database='headhunter')

The queries table stores a list of our search queries, having the following columns: query type, level, career field, and search phrase. The last column contains logical operators, for instance, we can get more results by putting logical ANDs between “Python”, “data” and “analysis”.

edata@2x.png

The search results may not always match the expectations, chiefs, marketers, and administrators can accidentally get into our database. To prevent this, we will write a function named check_name(name), it will accept a vacancy name and return a boolean value, depending on the match.

def check_name(name):
    bad_names = [r'курьер', r'грузчик', r'врач', r'менеджер по закупу',
           r'менеджер по продажам', r'оператор', r'повар', r'продавец',
          r'директор магазина', r'директор по продажам', r'директор по маркетингу',
          r'кабельщик', r'начальник отдела продаж', r'заместитель', r'администратор магазина', 
          r'категорийный', r'аудитор', r'юрист', r'контент', r'супервайзер', r'стажер-ученик', 
          r'су-шеф', r'маркетолог$', r'региональный', r'ревизор', r'экономист', r'ветеринар', 
          r'торговый', r'клиентский', r'начальник цеха', r'территориальный', r'переводчик', 
          r'маркетолог /', r'маркетолог по']
    for item in bad_names:
        if re.match(item, name):
            return True

Moving further, we need to create a while loop to collect data non-stop. Iterate over the Dataframe queries selecting the type, level, field, and search phrase columns. Send a GET request using a keyword to get the number of pages. Then we loop through the number of pages sending the same requests and populating vacancies_from_response with job descriptions. In the per_page parameter we specified 10, this is the max limit for the HH API. Since we didn’t pass any value to the area field, the results are collected worldwide.

while True:
   for query_type, level, direction, query_string in zip(queries['Query Type'], queries['Level'], queries['Career Field'], queries['Seach Phrase']):
           print(f'seach phrase: {query_string}')
           url = 'https://api.hh.ru/vacancies'
           par = {'text': query_string, 'per_page':'10', 'page':0}
           r = requests.get(url, params=par).json()
           added_at = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
           pages = r['pages']
           found = r['found']
           vacancies_from_response = []

           for i in range(0, pages + 1):
               par = {'text': query_string, 'per_page':'10', 'page':i}
               r = requests.get(url, params=par).json()
               try:
                   vacancies_from_response.append(r['items'])
               except Exception as E:
                   continue

Create a for loop to escape duplicate rows in our table. First, send a query to the database, verifying whether there is a vacancy with the same id and search phrase. If the verification was successful we then
pass the job title to check_name() and move on to the next one.

for item in vacancies_from_response:
               for vacancy in item:
                   if client.execute(f"SELECT count(1) FROM vacancies_short WHERE vacancy_id={vacancy['id']} AND query_string='{query_string}'")[0][0] == 0:
                       name = vacancy['name'].replace("'","").replace('"','')
                       if check_name(name):
                           continue

Now we need to extract all the necessary data from a job description. The table will contain empty cells, since some data may be missing.


View the code for extracting job description data

vacancy_id = vacancy['id']
                       is_premium = int(vacancy['premium'])
                       has_test = int(vacancy['has_test'])
                       response_url = vacancy['response_url']
                       try:
                           address_city = vacancy['address']['city']
                           address_street = vacancy['address']['street']
                           address_building = vacancy['address']['building']
                           address_description = vacancy['address']['description']
                           address_lat = vacancy['address']['lat']
                           address_lng = vacancy['address']['lng']
                           address_raw = vacancy['address']['raw']
                           address_metro_stations = str(vacancy['address']['metro_stations']).replace("'",'"')
                       except TypeError:
                           address_city = ""
                           address_street = ""
                           address_building = ""
                           address_description = ""
                           address_lat = ""
                           address_lng = ""
                           address_raw = ""
                           address_metro_stations = ""
                       alternate_url = vacancy['alternate_url']
                       apply_alternate_url = vacancy['apply_alternate_url']
                       try:
                           department_id = vacancy['department']['id']
                       except TypeError as E:
                           department_id = ""
                       try:
                           department_name = vacancy['department']['name']
                       except TypeError as E:
                           department_name = ""
                       try:
                           salary_from = vacancy['salary']['from']
                       except TypeError as E:
                           salary_from = "cast(Null as Nullable(UInt64))"
                       try:
                           salary_to = vacancy['salary']['to']
                       except TypeError as E:
                           salary_to = "cast(Null as Nullable(UInt64))"
                       try:
                           salary_currency = vacancy['salary']['currency']
                       except TypeError as E:
                           salary_currency = ""
                       try:
                           salary_gross = int(vacancy['salary']['gross'])
                       except TypeError as E:
                           salary_gross = "cast(Null as Nullable(UInt8))"
                       try:
                           insider_interview_id = vacancy['insider_interview']['id']
                       except TypeError:
                           insider_interview_id = "cast(Null as Nullable(UInt64))"
                       try:
                           insider_interview_url = vacancy['insider_interview']['url']
                       except TypeError:
                           insider_interview_url = ""
                       area_url = vacancy['area']['url']
                       area_id = vacancy['area']['id']
                       area_name = vacancy['area']['name']
                       url = vacancy['url']
                       published_at = vacancy['published_at']
                       published_at = datetime.strptime(published_at,'%Y-%m-%dT%H:%M:%S%z').strftime('%Y-%m-%d %H:%M:%S')
                       try:
                           employer_url = vacancy['employer']['url']
                       except Exception as E:
                           print(E)
                           employer_url = ""
                       try:
                           employer_alternate_url = vacancy['employer']['alternate_url']
                       except Exception as E:
                           print(E)
                           employer_alternate_url = ""
                       try:
                           employer_logo_urls_90 = vacancy['employer']['logo_urls']['90']
                           employer_logo_urls_240 = vacancy['employer']['logo_urls']['240']
                           employer_logo_urls_original = vacancy['employer']['logo_urls']['original']
                       except Exception as E:
                           print(E)
                           employer_logo_urls_90 = ""
                           employer_logo_urls_240 = ""
                           employer_logo_urls_original = ""
                       employer_name = vacancy['employer']['name'].replace("'","").replace('"','')
                       try:
                           employer_id = vacancy['employer']['id']
                       except Exception as E:
                           print(E)
                       response_letter_required = int(vacancy['response_letter_required'])
                       type_id = vacancy['type']['id']
                       type_name = vacancy['type']['name']
                       is_archived = int(vacancy['archived'])

The last field is the work schedule. If there is mentioned a fly-in-fly-out method, these kinds of job postings will be skipped.

try:
    schedule = vacancy['schedule']['id']
except Exception as E:
    print(E)
    schedule = ''"
if schedule == 'flyInFlyOut':
    continue

Next, we create a list of obtained variables, replacing None values with empty strings to escape errors with Clickhouse and insert them into the table.

vacancies_short_list = [added_at, query_string, query_type, level, direction, vacancy_id, is_premium, has_test, response_url, address_city, address_street, address_building, address_description, address_lat, address_lng, address_raw, address_metro_stations, alternate_url, apply_alternate_url, department_id, department_name,
salary_from, salary_to, salary_currency, salary_gross, insider_interview_id, insider_interview_url, area_url, area_name, url, published_at, employer_url, employer_logo_urls_90, employer_logo_urls_240,  employer_name, employer_id, response_letter_required, type_id, type_name, is_archived, schedule]
for index, item in enumerate(vacancies_short_list):
    if item is None:
        vacancies_short_list[index] = ""
tuple_to_insert = tuple(vacancies_short_list)
print(tuple_to_insert)
client.execute(f'INSERT INTO vacancies_short VALUES {tuple_to_insert}')

Connecting Tableau to the data source

Unfortunately, we can’t work with databases in  Tableau Public, that’s why we decided to connect our Clickhouse Database to Google Sheets. With this in mind, we picked the following libraries: gspread and oauth2client for accessing Google Spreadsheets API, and schedule for task scheduling.

Refer to our previous article where we used  Google Spreadseets API for  Collecting Data on Ad Campaigns from VK.com

import schedule
from clickhouse_driver import Client
import gspread
import pandas as pd
from oauth2client.service_account import ServiceAccountCredentials
from datetime import datetime

scope = ['https://spreadsheets.google.com/feeds', 'https://www.googleapis.com/auth/drive']
client = Client(host='54.227.137.142', user='default', password='', port='9000', database='headhunter')
creds = ServiceAccountCredentials.from_json_keyfile_name('credentials.json', scope)
gc = gspread.authorize(creds)

The update_sheet() function will transfer all data from Clickhouse to a Google Sheets table:

def update_sheet():
   print('Updating cell at', datetime.now())
   columns = []
   for item in client.execute('describe table headhunter.vacancies_short'):
       columns.append(item[0])
   vacancies = client.execute('SELECT * FROM headhunter.vacancies_short')
   df_vacancies = pd.DataFrame(vacancies, columns=columns)
   df_vacancies.to_csv('vacancies_short.csv', index=False)
   content = open('vacancies_short.csv', 'r').read()
   gc.import_csv('1ZWS2kqraPa4i72hzp0noU02SrYVo0teD7KZ0c3hl-UI', content.encode('utf-8'))

Using schedule to run our function every day at 1:00 PM (UTC):

schedule.every().day.at("13:00").do(update_sheet)
while True:
   schedule.run_pending()

What’s the final point?

Roman created an informative dashboard based on this data.
3-4.jpg https://revealthedata.com/examples/hh/

And made a youtube video with a detailed explanation of the dashboard features.

Key Insights

  1. Data Analysts specializing in BI are most in-demand in the job market since the highest number of search results were returned with this query. However, the average salary is higher in Product Analyst and BI-analyst openings.
  2. Most of the postings were found In Moscow, where the average salary is 10-30K RUB higher than in Saint Petersburg and 30-40K higher than in other regions.
  3. Top highly paid positions: Head of Analytics (110K RUB per month on avg.), Database Engineer (138K RUB per month), and Head of Machine Learning (250K RUB per month).
  4. The most useful skills to have are a solid knowledge of Python with Pandas and Numpy, Tableau, Power BI, ETL, and Spark. Most of the posings found contained these requirements and were highly paid than any others. For Python programmers, it’s more valuable to have expertise with Matplotlib than Plotly.

View the code on  GitHub

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