Python while循环不中断

Question

I'm a new programmer and I'm trying to make a rudimentary password generator. But I keep getting this problem where my while loop never breaks.

l1 = 'q w e r t y u i o p a s d f g h j k l z x c v b n m 1 2 3 4 5 6 7 8 9 0'
l2 = l1.split()


def genpass(n):
    x = 0       if x == 0:
        password = ''
    if n < 100:
        while n > x:
            password = password + random.choice(l2)
            x + 1
        print(password)
    else:
        print 'Sorry, too long'

Can someone tell me what I'm doign wrong? Thanks.

Answer 1

You never change n or x here:

while n > x:
    password = password + random.choice(l2)
    x + 1

So if the condition was True initially it will always stay True and loop infinitely. Need to do x = x + 1

Incidentally this is the exact sort of bug that Pylint would catch for you.

Answer 2

Please consider the following:

1) Obvious condition

    x = 0
    if x == 0:
        password = ''

You define x = 0, and then checks if x equals 0. It is invariably True. Hence, you can change it this way:

    x = 0
    password = ''

2) While loop never ends

Before you had:

while n > x:
    [some code]
    x + 1        # here was your mistake

Consider these two ways you can add 1 to the variable x :

x = x + 1

or

x += 1

Both mean the same thing.

For further enlightment: https://docs.python.org/3/reference/simple_stmts.html#augmented-assignment-statements

Answer 3

import random
l1 = 'q w e r t y u i o p a s d f g h j k l z x c v b n m 1 2 3 4 5 6 7 8 9 0'
l2 = l1.split()

def genpass(n):
  password = ''
  x = 0

  if n < 100:
    while n > x:
      password = password + random.choice(l2)
      x = x + 1
    print(password)
  else:
    print 'Sorry, too long'

genpass(10)

Answer 4

Can this help? :p

import random

l1 = 'q w e r t y u i o p a s d f g h j k l z x c v b n m 1 2 3 4 5 6 7 8 9 0'
l2 = list(l1.split())


def genpass(n):
    x = 0
    password=[]
    if n < 100:
        while n > x:
            password.append(random.choice(l2))
            x+=1
        return ''.join(password)
    else:
        return('Sorry, too long')

#example with 14 char
print(genpass(14))

Answer 5

You made quite a few errors in your code. What is x+1? It will be x=x+1. Please go through the basics first. Why are you checking if x==0, right after assigning x=0? Don't you think the if will always be yes? Your code in a cleaned format. Hope this works.

import random
l1 = 'q w e r t y u i o p a s d f g h j k l z x c v b n m 1 2 3 4 5 6 7 8 9 0'
l2 = l1.split()


def genpass(n):
    x = 0
    password = ''
    if n < 100:
        while n > x:
            password = password + random.choice(l2)
            x=x + 1
        print(password)
    else:
        print ('Sorry, too long')

print("Enter how long you want your password to be")
genpass(int(input()))

Answer 6

You can try this, I've upgraded a little to generate more complex password.

import random

lower = 'q w e r t y u i o p a s d f g h j k l z x c v b n m'
nums = '1 2 3 4 5 6 7 8 9 0'.split()
upper = lower.upper().split()
spcl = '; ! # @ & $ '.split()
all = lower.split() + nums + upper + spcl

def genpass(n):
    x = 0
    if x == 0:
        password = ''
    if n < 100:
        while n > x:
            password = password + random.choice(all)
            x=x + 1
        print(password)
    else:
        print('Sorry, too long')
# generates a sample password
genpass(10)