"".join() in python 3.7 not working inside def

Question

I'm trying to generate a unique password with a function. Everything works fine, except "".join. Help me see whats the problem in the code? Using Python 3.7.

My code:

import random
import string


def password():
    a = []
    letters = string.ascii_letters
    symbols = string.punctuation
    for element in range(6):
        a.append(random.randint(0, 10))
        a.append(random.choice(letters))
        a.append(random.choice(symbols))
    random.shuffle(a)
    print(''.join(str(a)))


password()

Without `str` I get error that says "expected str instance, int found" ? And return makes no difference for `"".join()`. I've tried. Thank you both — Sosofofie, Mar 12 '19 at 19:46
`str(a)` is converting your list to string representation. use `map(str,a)` instead — mad_, Mar 12 '19 at 19:47
ah, since the list contains ints, use `''.join(str(x) for x in a)` — Phydeaux, Mar 12 '19 at 19:49

Phydeaux · Accepted Answer · 2019-03-12T20:04:57.707

When you call join over str(a), you are first converting the list to a string, and then joining over every character in the stringified list.

What you want to do instead is convert each element in a to a string. You should use a generator expression, like this:

''.join(str(x) for x in a)

Alternatively, you can use the built-in function map(function, iterable), which is useful in the general case when you want to return a new iterable containing the results of function applied to every element in iterable. So you would use:

''.join(map(str, a))

It's basically a matter of taste as to which you find more readable.

"".join() in python 3.7 not working inside def

1 Answers1