CODEWITHSUNDEEP
pythonregexpandas
The Singularity
The Singularity

Reputation: 2698

Extracting a specific word using Regex in Pandas

I'm trying to extract the name of the country from the following dataframe

country
0   NaN
1   Country: America
2   Country: France ...More CountriesFranceNorwayP...
3   NaN
4   Country: India

using the following regex statement

import re
regex = re.compile(\
    r"Country: (?P<country>\w+)"
    )

df['country'] = df['country'].str.extractall(regex).droplevel(1)

However it returns

country
0   NaN
1   NaN
2   NaN
3   NaN
4   NaN

Instead of returning

country
0   NaN
1   America
2   France
3   NaN
4   India

What am I missing out on?

Please Advise

Upvotes: 2

Views: 778

Answers (2)

Mayank Porwal
Mayank Porwal

Reputation: 34086

You can also avoid regex and use Series.str.split:

In [86]: df = pd.DataFrame({'country' : [np.nan, 'Country: America', 'Country: France ... More countries...', np.nan, 'Country: India']})

In [87]: df
Out[87]: 
                                 country
0                                    NaN
1                       Country: America
2  Country: France ... More countries...
3                                    NaN
4                         Country: India

In [94]: df.country.str.split(':').str[1].str.split().str[0]
Out[94]: 
0        NaN
1    America
2     France
3        NaN
4      India
Name: country, dtype: object

Upvotes: 1

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627536

You can use extract:

df['country'] = df['country'].str.extract(r'Country:\s*(\w+)')

Pandas test:

import pandas as pd
import numpy as np
df = pd.DataFrame({'country' : [np.nan, 'Country: America', 'Country France ... More countries...']})
df['country'].str.extract(r'Country:\s*(\w+)')
#          0
# 0      NaN
# 1  America
# 2      NaN

Upvotes: 1

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