Select subset of Data Frame rows based on a list in Pandas

Question

I have a data frame df1 and list x:

In [22] : import pandas as pd
In [23]: df1 = pd.DataFrame({'C': range(5), "B":range(10,20,2), "A":list('abcde')})
In [24]: df1
Out[24]:
   A   B  C
0  a  10  0
1  b  12  1
2  c  14  2
3  d  16  3
4  e  18  4

In [25]: x = ["b","c","g","h","j"]

What I want to do is to select rows in data frame based on the list. Returning

   A   B  C
1  b  12  1
2  c  14  2

What's the way to do it? I tried this but failed.

df1.join(pd.DataFrame(x),how="inner")

Answer 1

Use isin to return a boolean index for you to index into your df:

In [152]:

df1[df1['A'].isin(x)]
Out[152]:
   A   B  C
1  b  12  1
2  c  14  2

This is what isin is returning:

In [153]:

df1['A'].isin(x)
Out[153]:
0    False
1     True
2     True
3    False
4    False
Name: A, dtype: bool