- all countrieson the population maps we made in this sectionour program couldn' automatically find two-letter codes for about countries work out which countries are missing codesand look through the countries dictionary for the codes add an ifelif block to get_country_code(so it returns the correct country code values for these specific countriesif country_name ='yemenrep return 'yeelif --snip-place this code after the countries loop but before the return none statement when you're finishedyou should see more complete map - gross domestic productthe open knowledge foundation maintains data set containing the gross domestic product (gdpfor each country in the worldwhich you can find at the json version of this data setand plot the gdp of each country in the world for the most recent year in the data set - choose your own datathe world bank maintains many data sets that are broken down for information on each country worldwide go to data worldbank org/indicatorand find data set that looks interesting click the data setclick the download data linkand choose csv you'll receive three csv filestwo of which are labeled metadatause the third csv file write program that generates dictionary with pygal' two-letter country codes as its keys and your chosen data from the file as its values plot the data on worldmap and style the map as you like - testing the country_codes modulewhen we wrote the country_codes modulewe used print statements to check whether the get_country_code(function worked write proper test for this function using what you learned in summary in this you learned to work with online data sets you learned how to process csv and json filesand extract the data you want to focus on using historical weather datayou learned more about working with matplotlibincluding how to use the datetime module and how to plot multiple data series on one chart you learned to plot country data on world map in pygal and to style pygal maps and charts downloading data