CODEWITHSUNDEEP
pythonpython-3.xpandascompare
Slartibartfast
Slartibartfast

Reputation: 1190

Comparing entries in dataframes in pandas

I have 2 identical dataframes, we can use this as an example.

import pandas as pd
import numpy as np

data = {'name': ['Sheldon', 'Penny', 'Amy', 'Penny', 'Raj', 'Sheldon'],
                'episodes': [42, 24, 31, 29, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}
data1 = {'name': ['Sheldon', 'Penny', 'Amy', 'Penny', 'Raj', 'Sheldon'],
                'episodes': [12, 32, 31, 32, 37, 40],
                'gender': ['male', 'female', 'female', 'female', 'male', 'male']}    

df1 = pd.DataFrame(data1, columns = ['name','episodes', 'gender'])    
df = pd.DataFrame(data, columns = ['name','episodes', 'gender'])
for names in df['name']:
    if (df[df['name'].str.contains(f'{names}')]['episodes']).any() == (df1[df1['name'].str.contains(f'{names}')]['episodes']).any():
        print('True')
        
    else:
        print('False')

It is checking if the number of episodes are different between the two dataframes and should print false where they are different episodes. But I am getting all True

True
True
True
True
True
True

Why is it not printing false?

Upvotes: 1

Views: 70

Answers (4)

BENY
BENY

Reputation: 323266

We can just try merge

df.merge(df1,on='name',how='left').eval('episodes_x==episodes_y')

Upvotes: 1

Corralien
Corralien

Reputation: 120419

Use set_index then compare episodes columns:

>>> df.set_index('name')['episodes'] == df1.set_index('name')['episodes']
name
Sheldon    False
Penny      False
Amy         True
Penny      False
Raj         True
Sheldon     True
Name: episodes, dtype: bool

Upvotes: 3

Hien Vo
Hien Vo

Reputation: 43

I think you meant to put data1 into df1? Right now you have created df1 and df both from data alone. Also, you don't really need to go through it row by row. (df == df1)['episodes'] should give you what you want.

Upvotes: 0

ashkangh
ashkangh

Reputation: 1624

you can use .eq() method:

print(df.episodes.eq(df1.episodes))

0    False
1    False
2     True
3    False
4     True
5     True
Name: episodes, dtype: bool

Upvotes: 2

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