Replace for loop to search index position

[illmattic]

Hi

I have following code which searches for index position of matching string without having to match everything:

sheet_num = []
for x in range(len(list_of_sheets)):
    if sheet_match in list_of_sheets[x]:
            sheet_num.append(x)

I'm looking for a better way to accomplish this as my code is filled with many occurrences of this type of for loop appending to an empty list.

I thought about:

list(map(lambda x: sheet_match in x, list_of_sheets))

But it returns a list of boolean values instead of the index position of the match. I'm sure its simple but I'm not so competent in Python to know it.

Thanks
Matt