mdp = ['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', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0']

def m(r):
	for z in range(r):
		print(choice(mdp), end='')

print(m(8))
02kqpvqnNone

(Feb-08-2021, 08:17 AM)bowlofred Wrote: You're executing print() in two locations.

The first is inside the function. That's where you print the 8 characters.

But then outside the function (on line 7) you print the return value from the function. As the function doesn't return anything explicitly, it defaults to returning None, and that is printed.

(Feb-08-2021, 08:21 AM)thortank Wrote: Just took the second print away and now it works

(Feb-08-2021, 08:49 AM)buran Wrote:

(Feb-08-2021, 08:21 AM)thortank Wrote: Just took the second print away and now it works

The better approach is to construct the desired string inside the function and then make your function return this string. Then print the returned value outside the function. This way it is reusable - e.g. you can print, or bind to a name for later use. At the moment your function just prints something - not great use.

"""
Programm to output random lower case ascii characters + digits
"""

import string
from random import choice, choices


MDP = string.ascii_lowercase + string.digits


def random_chars(length):
    chars = []
    for _ in range(length):
        chars.append(choice(MDP))
    return "".join(chars)


def random_chars_easy(length):
    return "".join(choices(MDP, k=length))


if __name__ == "__main__":
    print(random_chars(12))

• string module
  
• random: functions-for-sequences
  
• str.join
  

chars = ["a", "b", "c"]

print("".join(chars))
print("-".join(chars))

Output:
abc
a-b-c

from random import choices # plural

chars = "abcdefgh1234"
print(choices(chars, k=5))

Output:
['4', 'a', 'd', 'e', 'e']

def foo():
    pass


print(foo())

Output:
None

(Feb-08-2021, 10:54 AM)DeaD_EyE Wrote:

"""
Programm to output random lower case ascii characters + digits
"""

import string
from random import choice, choices


MDP = string.ascii_lowercase + string.digits


def random_chars(length):
    chars = []
    for _ in range(length):
        chars.append(choice(MDP))
    return "".join(chars)


def random_chars_easy(length):
    return "".join(choices(MDP, k=length))


if __name__ == "__main__":
    print(random_chars(12))

You should visit the documentation:

• string module
  
• random: functions-for-sequences
  
• str.join
  

chars = ["a", "b", "c"]

print("".join(chars))
print("-".join(chars))

Output:
abc
a-b-c

from random import choices # plural

chars = "abcdefgh1234"
print(choices(chars, k=5))

Output:
['4', 'a', 'd', 'e', 'e']

I hope that are enough examples to understand the code.

Another hint:

If you make a function without any return statement inside, the object None is returned implicit. For example print was in Python 2 a statement. Now since long time, print is a function. Also the print function return a None.

That's why you got a None.

def foo():
    pass


print(foo())

Output:
None

def random_chars(length):
    chars = []
    for _ in range(length):
        chars.append(choice(MDP))
    return "".join(chars)

Quote:What is the chars.append and return "".join? What is it used for?

chars = [] # <- empty list

"" # < this is an empty str literal
   # and you can access the methods of str with a . dot

abc_as_str = "".join(["a", "b", "c"])

Quote:There are also the if __name__ == "__main__":... What is __name__ and "__main__"?

python3 your_program.py