find_all_indices_in_list_by_value

def all_indices(value, qlist):
    indices = []
    idx = -1
    while True:
        try:
            idx = qlist.index(value, idx + 1)
            indices.append(idx)
        except ValueError:
            break
    return indices

print(all_indices("foo", ["foo","bar","baz","foo"]))