import random

valid_characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890"

password = ""

# range is a function that takes an integer as input and returns a list of
# numbers from 0 up to that upper bound. For example, range(10) produces
#
#    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
#
# Here we use range as a way to loop a certain number of times (in this case 10
# times), to produce a password of a certain length.
for i in range(10):
    password = password + random.choice(valid_characters)

print(password)