Is there a method to output the position of all of the occurrences of a value in a list?

Answer 1

I'm not aware of anything built in that outputs all of the indexes. You can use list_name.index(value) to find the index of the first item matching value in the list.

Here's a function that would return the info you want
def all_indexes(array, value):
out = []
for index, item in enumerate(array):
if item == value:
out.append(index)
return out

Or if you'd prefer a lambda function you can use this
all_indexes = lambda array, value: [index for index, item in enumerate(array) if item == value]

I typed this on my phone, so the spacing may be wrong. Also I'm betting my lambda violated pep8, so i might suggest making it 2 lines