'int' object is not iterable while creating dictionary

I'm trying to create a dictionary in python. However, I want to create the dictionary using the random values. The desired output should be in the form {'a':1, 'b':2} in the format.

import numpy as np
import pandas as pd
import random
import string

value = np.random.random(10)
np.random.seed(42)
key = list(np.random.choice(list(string.ascii_lowercase), 10))
key, value

def map_values(key, value):
i = len(key)
j = len(value)
for i in len(key):
    print('key[i]' +'value[j]')
    i = i+1
    j = j+1
    return map_values()

map_values(key, value)

However while running the above code, I got the error 'int' object is not iterable. Can someone explain the reason for the error and rectify the code as I'm new to python and trying to learn it.