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pythonpandasdata-comparison

Comparing two columns using pandas


Hi I want to compare two columns in a pandas dataframe to see if a value is in any row of a column.

Table: 1

| Animals_1 |  Count |
|-----------|--------|
|    Dog    |    1   |
|    Cat    |    2   |
|  Squirrel |    3   |

Table:2

| Animals_2 |  Count |
|-----------|--------|
|  Giraffe  |    2   |
|    Dog    |    1   |
|    Cat    |    1   |

So I want to check to see if Dog from table 1 is in any rows in column 1 of table 2. I am new to python and using pandas to read table dataframe.


Solution

  • import pandas as pd
    df1 = pd.DataFrame({"Animals_1":["Dog","Cat","Squirrel"],"Count":[1,2,3]})
    df2 = pd.DataFrame({"Animals_2":["Giraffe","Dog","Cat"],"Count":[2,1,1]})
    df1['compare'] = df1['Animals_1'].isin(df2['Animals_2'])
    

    Output df1:

    Animals_1 Count compare
    0 Dog 1 True
    1 Cat 2 True
    2 Squirrel 3 False