python .index returns code example
Example 1: python find index by value
>>> ["foo", "bar", "baz"].index("bar")
1
Example 2: python, list, index function
# vowels list
vowels = ['a', 'e', 'i', 'o', 'i', 'u']
# index of 'e' in vowels
index = vowels.index('e')
print('The index of e:', index)
# element 'i' is searched
# index of the first 'i' is returned
index = vowels.index('i')
print('The index of i:', index)