Comparing two columns using pandas

Question

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.

score 1 · Accepted Answer · answered Mar 12 '21 at 21:15

1

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

answered Mar 12 '21 at 21:15

RJ Adriaansen

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I was going to use .iloc in a for loop, but this way is much better. Thank you. – Harry007 Mar 12 '21 at 23:36

Comparing two columns using pandas

1 Answers1