find the index of a value in array python code example

Example 1: how to find item in list python without indexnig

>>> ["foo", "bar", "baz"].index("bar")
1

Example 2: get index of item in list

list.index(element, start, end)

Example 3: numpy find index of matching values

import numpy as np
# init arrays
a = np.array([1,2,3,2,3,4,3,4,5,6])
b = np.array([7,2,10,2,7,4,9,4,9,8])

#using enumerate, list comprehension and set
print([key for key, val in enumerate(a) if val in set(b)])
# output
# [1, 3, 5, 7]