search an element in pandas series

[perfringo]

Agree. isin() is searching for element 7 while each element in my series is a LIST. Hence returning false.
Is there a way, we can use somehow still use isin() to return following:

You know that every element in series is list. Does list have isin method?

Straightforward approach to achieve desired result could be with helper function:

import pandas as pd

s = pd.Series(
                {
                    'A': [1,2,3,4,5],
                    'B': [6,7,8],
                    'C': [9,10,11,12]
                })

def helper(item):
    return 7 in item

print(s.apply(helper))

A    False
B     True
C    False
dtype: bool

Instead helper function lambda can be used:

print(s.apply(lambda item: 7 in item))

Of course, isin can be "used" as well: "explode series, compare, group boolean values back by index, find if any in group is true":

print(s.explode().isin([7]).groupby(level=0).apply(any))

A    False
B     True
C    False
dtype: bool