Pandas and Seaborn are one of the most useful data science related Python libraries. The first one provides an easy to use and high-performance data structures and methods for data manipulation. The latter is build on top of matplotlib and provides a high-level interface for drawing attractive statistical graphics. How do they work?

Let’s check it out using World Bank GDP data from 10 central European countries – Poland, Germany, Belarus, the Czech Republic, the Slovak Republic, Hungary, Estonia, France, Ukraine and the United Kingdom.

Just want to run the project? You can find it here: The World GDP Analysis Project

What are we looking for?

The question – How far in economic development eastern Europe countries are relative to developed countries like Germany and France?

To answer it we need to analyze four GDP factors – GDP per capita (US$), GDO per capita growth (annual %), GDP growth (annual %) and GDP (current US$).

The data from the World Bank (from the World Development Indicators website to be exact) are in an open format and have good history records for many countries that include a number of economic and social indicators.

We chose the years 1990 – 2016 because only these were available for the selected indicators.

You can find the data here.

The code

First, we load the data from the CSV file. Then we remove the last 5 lines, because they contain empty values and information about the date of the last data update. In addition, we have to remove the column with the year 2016, because, as it turned out it is empty (no data). “gdp.replace” is responsible for the replacement of two dots, symbolizing the empty NaN.

In the course of further work with DataFrame I received mysterious errors and at first, I was not able to determine what was wrong. After some time I decided to check the types of the individual columns:

To my surprise dates from 1990 to 1995 didn’t have the data type float64 only object, so I decided to be sure all the columns of years to convert to numeric values. For this purpose, I select  columns from 4 up to the end (that is, all of the years) and with use of “apply” method ‘I applied the function “pd.to_numeric“. It converts all years to a floating point number.

In each row, was the name of the country, its code, the name of a series of data from the World Bank, its code, and in subsequent columns the years. Such arrangement of the data was not too comfortable so I decided to reindex the table using the functions “pivot_table”

This has changed dataframe from form:

To this one.

That way I can pull any economic indicator and immediately have all the countries along with all the years.

Now I can easily visualize 4 selected indicators. For nicer graphs import Seaborn and set the color palette so that each line on the graph was plotted with a different color. Try comparing charts with and without Seaborn.

Drawing directly with the pandas is really simple – just for our pivot table choose the interesting indicator, then transpose the data (function .T) and plot (, plot ‘).

The first two charts

1. GDP (current US$), data from World bank

2. GDP per capita, data from World bank

Let’s try to perform a simple regression from the GDP data to see if there is a chance that one day we can catch up with Germany. This time we will use the “lmplot” function from the Seaborn library, except that the data must lead to a form of time series.

From the data in the form of a table with countries as columns, we need to create a table in which we will have only three columns [years, the country GDP]. We do this through a series of operations, the removal of the index, because our table at the beginning of the year is indexed (unique rows), changes of the name of the column. The key operation here is the “melt” function that transmits the data from the column and adds them into the next rows. So that we are able to make the following transformation. The attached images omitted part of the columns and rows but I hope its clear.

 

We should get a result similar to this:

 

Thanks!

Be sure to check also how ca you launch the project in PLON after importing it into your PLON account.

Important link

• The World GDP Analysis on the PLON platform.
  • Github version
• A great 10 minutes to pandas tutorial
• The PLON Platform