CODEWITHSUNDEEP
pythondataframe
Min.Y Ku
Min.Y Ku

Reputation: 25

how to compare each columns in python

There are three columns:

A B Latest Date Type
2021-05-28 2021-05-01 2021-05-28 A
2021-03-01 2021-03-30 2021-03-30 B

If "Latest Date" is same with A, the value of "Type" is A. If "Latest Date" is same with B, the value of "Type" is B.

How can I compare each columns A, B whether each element is same with Latest Date or not?

Upvotes: 2

Views: 99

Answers (5)

Andreas
Andreas

Reputation: 9207

You can use the following, which can handle additional columns e.g. column C, D, E ... as well. And is able to give you both values if A and B would be identical.

df.join(df.reset_index().melt(id_vars=['index', 'Latest Date'], value_vars=['A','B'], var_name='Type').query('value==`Latest Date`').groupby(['index'])['Type'].apply(list))

            A           B Latest Date Type
0  2021-05-28  2021-05-01  2021-05-28  [A]
1  2021-03-01  2021-03-30  2021-03-30  [B]

Upvotes: 0

Gamopo
Gamopo

Reputation: 1598

You can use something like this:

df['type']= df.apply(lambda x: 'A' if x['A']==x['Latest_date'] else 'B')

Upvotes: 1

sophocles
sophocles

Reputation: 13831

You can use numpy.where and compare Latest Date with A and B, and assign values in the Type column:

import numpy as np

df['Type'] = np.where(
    df['Latest Date'].eq(df['A']),'A',  # Return A if column Latest Date equals column A
    np.where(
    df['Latest Date'].eq(df['B']),'B',  # Return B if column Latest Date equals column B 
    'Not A or B'))                      # If none are satisfied return 'Not A or B'

            A           B Latest Date Type
0  28/05/2021  01/05/2021  28/05/2021    A
1  01/03/2021  30/03/2021  30/03/2021    B

Upvotes: 0

SeaBean
SeaBean

Reputation: 23217

You can use .loc to locate the rows with the respective conditions of column A or column B matching column Latest Date and assign values to Type accordingly, as follows:

df.loc[df['A'] == df['Latest Date'], 'Type'] = 'A'
df.loc[df['B'] == df['Latest Date'], 'Type'] = 'B'

Result:

print(df)


            A           B Latest Date Type
0  2021-05-28  2021-05-01  2021-05-28    A
1  2021-03-01  2021-03-30  2021-03-30    B

Upvotes: 1

meadhu
meadhu

Reputation: 11

data_list = [
    {"A": "2021-05-28", "B": "2021-05-01", "latest_date": "2021-05-28", "type": ""},
    {"A": "2021-03-01", "B": "2021-03-30", "latest_date": "2021-03-30", "type": ""}
]

for index, item in enumerate(data_list):
    if item['latest_date'] == item['A']:
        item['type'] = "A"
    elif item['latest_date'] == item['B']:
        item['type'] = "B"
    data_list[index].update(item)

print(data_list)

Upvotes: 0

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