Random Password Generator 1: Edits 1 <Faulty>

import math
import random
alpha = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
print('Would you like a random password suggestion generator', 'Yes or No')
permissionRandomGenerator = input().lower()
print('How long do you want your password?')
lengthRandomGenerator = int(input())
if permissionRandomGenerator == 'yes':
    def a():
        return math.floor(random.random()*10)
    def b():
        return alpha[math.floor(random.random()*27)]
    c = []
    d = 0
    def changeCase(f):
        g = round(random.random())
        if g == 0:
            return f.lower()
        elif g == 1:
            return f.upper()
    while d < lengthRandomGenerator:
        c.insert(d, a())
        d = d + 1
        if d >= lengthRandomGenerator:
            break
        c.insert(d, b())
        c[d] = changeCase(c[d])
        d = d + 1
        continue
    d = 0
    if lengthRandomGenerator <= 0:
        print('It has to be longer than that')
    elif lengthRandomGenerator >= 25:
        print('I can\'t generate a password that long')
    elif math.isnan(lengthRandomGenerator):
        print('error: not valid data type')
    else:
        while d < (len(c)-1):
            e = c[d]
            print(e)
            d = d + 1
    d = 0
    c = []
elif permissionRandomGenerator == 'no':
    print('Too bad...')
else:
    print('You had to answer Yes or No')