How to replace dataframe columns country name with continent? - python-3.x

Question

I have Dataframe like this.
problem.head(30)
Out[25]:
Country
0 Sweden
1 Africa
2 Africa
3 Africa
4 Africa
5 Germany
6 Germany
7 Germany
8 Germany
9 UK
10 Germany
11 Germany
12 Germany
13 Germany
14 Sweden
15 Sweden
16 Africa
17 Africa
18 Africa
19 Africa
20 Africa
21 Africa
22 Africa
23 Africa
24 Africa
25 Africa
26 Pakistan
27 Pakistan
28 ZA
29 ZA
Now i want to replace the country name with the continent name. So the country name will be replace with its continent name.
What i did is, i have created all the Continent array(which is there in my data frame, i have 56 country),
asia = ['Afghanistan', 'Bahrain', 'United Arab Emirates','Saudi Arabia', 'Kuwait', 'Qatar', 'Oman',
'Sultanate of Oman','Lebanon', 'Iraq', 'Yemen', 'Pakistan', 'Lebanon', 'Philippines', 'Jordan']
europe = ['Germany','Spain', 'France', 'Italy', 'Netherlands', 'Norway', 'Sweden','Czech Republic', 'Finland',
'Denmark', 'Czech Republic', 'Switzerland', 'UK', 'UK&I', 'Poland', 'Greece','Austria',
'Bulgaria', 'Hungary', 'Luxembourg', 'Romania' , 'Slovakia', 'Estonia', 'Slovenia','Portugal',
'Croatia', 'Lithuania', 'Latvia','Serbia', 'Estonia', 'ME', 'Iceland' ]
africa = ['Morocco', 'Tunisia', 'Africa', 'ZA', 'Kenya']
other = ['USA', 'Australia', 'Reunion', 'Faroe Islands']
Now trying to replace using
dataframe['Continent'] = dataframe['Country'].replace(asia, 'Asia', regex=True)
where asia is my list name and Asia is text to be replace. But is not working
it only work for
dataframe['Continent'] = dataframe['Country'].replace(np.nan, 'Asia', regex=True)
So, help will be appreciated

Answer 1

Using apply with a custom function.
Demo:
import pandas as pd
asia = ['Afghanistan', 'Bahrain', 'United Arab Emirates','Saudi Arabia', 'Kuwait', 'Qatar', 'Oman',
'Sultanate of Oman','Lebanon', 'Iraq', 'Yemen', 'Pakistan', 'Lebanon', 'Philippines', 'Jordan']
europe = ['Germany','Spain', 'France', 'Italy', 'Netherlands', 'Norway', 'Sweden','Czech Republic', 'Finland',
'Denmark', 'Czech Republic', 'Switzerland', 'UK', 'UK&I', 'Poland', 'Greece','Austria',
'Bulgaria', 'Hungary', 'Luxembourg', 'Romania' , 'Slovakia', 'Estonia', 'Slovenia','Portugal',
'Croatia', 'Lithuania', 'Latvia','Serbia', 'Estonia', 'ME', 'Iceland' ]
africa = ['Morocco', 'Tunisia', 'Africa', 'ZA', 'Kenya']
other = ['USA', 'Australia', 'Reunion', 'Faroe Islands']
def GetConti(counry):
if counry in asia:
return "Asia"
elif counry in europe:
return "Europe"
elif counry in africa:
return "Africa"
else:
return "other"
df = pd.DataFrame({"Country": ["Sweden", "Africa", "Africa", "Germany", "Germany", "UK","Pakistan"]})
df['Continent'] = df['Country'].apply(lambda x: GetConti(x))
print(df)
Output:
Country Continent
0 Sweden Europe
1 Africa Africa
2 Africa Africa
3 Germany Europe
4 Germany Europe
5 UK Europe
6 Pakistan Asia

Answer 2

It would be better to store your country-to-continent map as a dictionary rather than four separate lists. You can do this as follows, starting with your current lists:
continents = {country: 'Asia' for country in asia}
continents.update({country: 'Europe' for country in europe})
continents.update({country: 'Africa' for country in africa})
continents.update({country: 'Other' for country in other})
Then you can use the Pandas map function to map continents to countries:
dataframe['Continent'] = dataframe['Country'].map(continents)