Comparing Items Different Data Frames With a WHILE Loop

[JoeDainton123]

Hello all

I was wondering if anyone could help with comparing items in one data frame with an items in another data frame.

I have 2 x data frames
DF_One
DF_TWO

I want to loop through all of the values in DF_One in the first column and compare this with all of the values in the first column in DF_Two.

The Code would be like:-

Do until the end of DF_One is reached
...Current_Value = value in row (t),column 1 of DF_One
......Do until the end of DF_Two is reached
.........if Current_Value = row(i), Column 1 in DF_Two
............print ("found")
.........end if
......i=i+1
t=t+1

I want to use a while loop and not the where function.

Can anyone help or just point me in the right direction.

Thank you.

[scidam]

There is .isin method, which provides this functionality.

import pandas as pd
df1 = pd.DataFrame({'x': pd.np.random.randint(1, 1000, size=200)})
df2 = pd.DataFrame({'x': pd.np.random.randint(1, 1000, size=100)}) 
df1.x.isin(df2.x)

Pure Python loops will be very slow in case of large dfs.