Human: index of an element in a list in. Assistant: 
Here is a Python function to index an element in a list

import numpy as np

def index_of_element(list, element):
    """
    >>> list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
    >>> index_of_element(list, 5)
    4
    """
    for i in range(len(list)):
        if list[i] == element:
            return i
    return -1

# Enter the array
a = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

# Calling the function
print((index_of_element(a, 5)))

#Remember to inspect code for bugs.