List Comprehension for Strings

Question

I have two lists as shown below. I want to find whether the strings inside the first list are in any of the strings in the second list. For some reason, I get an empty list when I try to run this.

For example: in list5, string 'apple' is in list6's 'I ate an apple'.

list5 = ['apple', 'mango', 'sherbet']
list6 = ['I ate an apple', 'I ate two apples', 'I love mango']
print ([x for i,x in enumerate(list5) if x in list6])

The exact same things run smoothly for a list of integers. Is there a different way of going through the strings?

list7 = [1, 2, 3, 4, 5]
list8 = [1, 2]
print ([x for i,x in enumerate(list7) if x in list8])  

Answer 1

You are checking if apple is in the list but you want to check if any string in the list contains apple

list5 = ['apple', 'mango', 'sherbet']
list6 = ['I ate an apple', 'I ate two apples', 'I love mango']
[x for x in list5 if any(x in item for item in list6)]
#['apple', 'mango']

EDIT

This creates a list of list in which contain the indexes of the sentence in the second list, which contain the word from the first list

list5 = ['apple', 'mango', 'sherbet']
list6 = ['I ate an apple', 'I ate two apples', 'I love mango', '2 apple', 'big apple', 'big mango']
[[i for i, sentence in enumerate(list6) if x in sentence] for x in list5]
#[[0, 1, 3, 4], [2, 5], []]

As I said in my comment a dictionary would be better in this situation

{x:[i for i,sen in enumerate(list6) if x in sen] for x in list5}
#{'apple': [0, 1, 3, 4], 'mango': [2, 5], 'sherbet': []}

And if only exact matches should be stored you can use this, but this does not work if the first list does not only contain words, for example if list5 contains "an apple" this does NOT work

{x:[i for i,sen in enumerate(list6) if any(x==item for item in sen.split())] for x in list5}
#{'apple': [0, 3, 4], 'mango': [2, 5], 'sherbet': []}

Answer 2

Your code is checking if x is a member of list6, when it seems like you want to know if x is a substring of any member in list6. You can do this using Python's reduce method (in functools with Python 3).

list5 = ['apple', 'mango', 'sherbet']
list6 = ['I ate an apple', 'I ate two apples', 'I love mango']

from functools import reduce
print([x for x in list5
         if reduce(lambda exist, s: exist or (x in s), list6, False)])
# ['apple', 'mango']

The reduce call is iterating through all members of list6 and checking if x is a substring, then or'ing those results against exist (which defaults to False here) to return True if it's found at least once. See the Python3 documentation for functools.reduce for a better idea of how it works.