Python Pandas: Check if string in one column is contained in string of another column in the same row

Question

I have a dataframe like this:

RecID| A  |B
----------------
1    |a   | abc 
2    |b   | cba 
3    |c   | bca
4    |d   | bac 
5    |e   | abc 

And want to create another column, C, out of A and B such that for the same row, if the string in column A is contained in the string of column B, then C = True and if not then C = False.

The example output I am looking for is this:

RecID| A  |B    |C 
--------------------
1    |a   | abc |True
2    |b   | cba |True
3    |c   | bca |True
4    |d   | bac |False
5    |e   | abc |False

Is there a way to do this in pandas quickly and without using a loop? Thanks

question from:https://stackoverflow.com/questions/43855685/python-pandas-check-if-string-in-one-column-is-contained-in-string-of-another-c

Answer 1

You need apply with in:

df['C'] = df.apply(lambda x: x.A in x.B, axis=1)
print (df)
   RecID  A    B      C
0      1  a  abc   True
1      2  b  cba   True
2      3  c  bca   True
3      4  d  bac  False
4      5  e  abc  False

Another solution with list comprehension is faster, but there has to be no NaNs:

df['C'] = [x[0] in x[1] for x in zip(df['A'], df['B'])]
print (df)
   RecID  A    B      C
0      1  a  abc   True
1      2  b  cba   True
2      3  c  bca   True
3      4  d  bac  False
4      5  e  abc  False