using element on a list as condition statement

[perfringo]

It is more efficient if you convert your list to a set just for comparison purpose. A list can have the same element multiple times, when converting it to a set, it ll only contain element once.

I think that using built-in any() is even more efficient approach. Due to short-circuiting nature it will stop if first match encountered. In real life scenarios this means that if there is a match you don't need to go through all items in list or convert whole list into set. One can craft such a code:

>>> target = 33
>>> lst = [11, 22, 33, 44, 55]  
>>> match = ['is not', 'is'][any(target == item for item in lst)]               
>>> f'{target} {match} in the list'                                             
'33 is in the list'                                                             
>>> target = 10                                                                 
>>> match = ['is not', 'is'][any(target == item for item in lst)]               
>>> f'{target} {match} in the list'                                             
'10 is not in the list'    

Instead of ['is not', 'is'] one can use ['not', ''] and put 'is' into string but it would be too cryptic for my taste.