import pandas as pd
import matplotlib.pyplot as plt

# I want only a few selected columns
selected_columns =  ['type','iso_country']

url = 'https://www.jre-training.com/Pandas/Data/airport-codes.csv'
orgin_df = pd.read_csv(url, usecols=selected_columns)

filter = orgin_df['type'] == 'large_airport'

selected_columns.remove('type')

filtered_df = orgin_df.loc[filter, selected_columns]
data_series = filtered_df.iso_country.value_counts()

#for (index, value) in data_series.iteritems():
#    print(index, value)

x_axis = data_series.index
y_axis = data_series.values
#print(x_axis)
#print(y_axis)

plt.hist(data_series.head(10))
plt.show()