P#25 Pandas Data Frame set_index() and reset_index()

 Data Frame set_index() and reset_index()

These methods are very useful. We can dynamically change re index and reset index with out any problem.

import pandas as  pd


drinks= pd.read_csv('http://bit.ly/drinksbycountry')

print(drinks.shape) #(193, 6)

print(drinks.index) #RangeIndex(start=0, stop=193, step=1)

print(drinks.columns)
"""Index(['country', 'beer_servings', 'spirit_servings', 'wine_servings',
       'total_litres_of_pure_alcohol', 'continent'],
      dtype='object')
"""

drinks.set_index('continent',inplace=True)


print(drinks.index)

"""
Index(['Asia', 'Europe', 'Africa', 'Europe', 'Africa', 'North America',
       'South America', 'Europe', 'Oceania', 'Europe',
       ...
       'Africa', 'North America', 'South America', 'Asia', 'Oceania',
       'South America', 'Asia', 'Asia', 'Africa', 'Africa'],
      dtype='object', name='continent', length=193)
"""

print(drinks.head())

"""
              country  ...  total_litres_of_pure_alcohol
continent               ...                              
Asia       Afghanistan  ...                           0.0
Europe         Albania  ...                           4.9
Africa         Algeria  ...                           0.7
Europe         Andorra  ...                          12.4
Africa          Angola  ...                           5.9

[5 rows x 5 columns]
"""

print(drinks.shape) #(193, 5)

print(drinks.loc['Europe', 'spirit_servings'])
"""
continent
Europe    132
Europe    138
....
Europe    237
Europe    126
Name: spirit_servings, dtype: int64
"""

drinks.index.name = None


print(drinks.index)

"""
Index(['Asia', 'Europe', 'Africa', 'Europe', 'Africa', 'North America',
       'South America', 'Europe', 'Oceania', 'Europe',
       ...
       'Africa', 'North America', 'South America', 'Asia', 'Oceania',
       'South America', 'Asia', 'Asia', 'Africa', 'Africa'],
      dtype='object', length=193)

"""

drinks.index.name='continent'

drinks.reset_index(inplace=True)  # Resetting Index inplace

print(drinks.head(2))

"""
 continent      country  ...  wine_servings  total_litres_of_pure_alcohol
0      Asia  Afghanistan  ...              0                           0.0
1    Europe      Albania  ...             54                           4.9

[2 rows x 6 columns]
"""

The above code snippets and output shows , how it is very easy to operate in Data Frames

Happy Learning @ AMET ODL!!!!