sample.py

from string import ascii_lowercase as lowercase
from string import ascii_uppercase as uppercase
from string import digits, punctuation
from random import randint, sample, shuffle

sources = [lowercase, digits, uppercase, punctuation]

def make_password(length, complexity):
    assert(length >= 4)
    assert(complexity >= 1 and complexity <= 4)

    pass_list = []
    
    # make sure we have the minimum for the complexities already present
    for n in range(complexity):
        pass_list.extend(sample(sources[n], 1))

    # now extend the list with N elements where N is total length minus complexity
    for x in range(length - complexity):
       # the elements will be get from any source that is covered by required complexity 
       pass_list.extend(sample(sources[randint(0, complexity - 1)], 1))

    # shuffle to look better
    shuffle(pass_list)

    return ''.join(pass_list)


if __name__ == '__main__':
    length = input('Please provide the size of your pass: ')
    complexity = input('Please provide the complexity of your pass (1 to 4): ')
    print(make_password(int(length), int(complexity)))