现在可以在这里使用一个新的库（python>=3.6）

from chancepy import Chance

random_string = Chance.string(length=10, pool="someLettersAndNumbers123")

一个简单的例子：

import string
import random
character = string.lowercase + string.uppercase + string.digits + string.punctuation
char_len = len(character)
# you can specify your password length here
pass_len = random.randint(10,20)
password = ''
for x in range(pass_len):
    password = password + character[random.randint(0,char_len-1)]
print password

面向安全的方法

我们对任何安全相关的建议都是避免“自己动手”，并使用经过专门安全审查的机密模块。

这来自文档的最佳实践部分：

import string
import secrets
alphabet = string.ascii_letters + string.digits
password = ''.join(secrets.choice(alphabet) for i in range(8))

由于您特别要求使用大写字母，因此您可以用ascii_capsaper替换ascii_cletters，或者只使用以下内容将密码大写：

password = password.upper()

不以安全为目的的标准方法

这个问题的规范方法（如指定）使用随机模块中的choices（）函数：

>>> from random import choices
>>> from string import ascii_uppercase, digits

>>> population = ascii_uppercase + digits
>>> str.join('', choices(population, k=6))
'6JWF1H'

我会这样做：

import random
from string import digits, ascii_uppercase

legals = digits + ascii_uppercase

def rand_string(length, char_set=legals):

    output = ''
    for _ in range(length): output += random.choice(char_set)
    return output

或者只是：

def rand_string(length, char_set=legals):

    return ''.join( random.choice(char_set) for _ in range(length) )

（1） 这将为您提供所有大写和数字：

import string, random
passkey=''
for x in range(8):
    if random.choice([1,2]) == 1:
        passkey += passkey.join(random.choice(string.ascii_uppercase))
    else:
        passkey += passkey.join(random.choice(string.digits))
print passkey 

（2） 如果您以后想在密钥中包含小写字母，那么这也可以：

import string, random
passkey=''
for x in range(8):
    if random.choice([1,2]) == 1:
        passkey += passkey.join(random.choice(string.ascii_letters))
    else:
        passkey += passkey.join(random.choice(string.digits))
print passkey  

一种无重复的随机生成器函数，使用一个集合来存储以前生成的值。注意，如果字符串或数量非常大，这将消耗一些内存，而且可能会稍微慢一点。发电机将在给定量或达到最大可能组合时停止。

代码：

#!/usr/bin/env python

from typing import Generator
from random import SystemRandom as RND
from string import ascii_uppercase, digits


def string_generator(size: int = 1, amount: int = 1) -> Generator[str, None, None]:
    """
    Return x random strings of a fixed length.

    :param size: string length, defaults to 1
    :type size: int, optional
    :param amount: amount of random strings to generate, defaults to 1
    :type amount: int, optional
    :yield: Yield composed random string if unique
    :rtype: Generator[str, None, None]
    """
    CHARS = list(ascii_uppercase + digits)
    LIMIT = len(CHARS) ** size
    count, check, string = 0, set(), ''
    while LIMIT > count < amount:
        string = ''.join(RND().choices(CHARS, k=size))
        if string not in check:
            check.add(string)
            yield string
            count += 1


for my_count, my_string in enumerate(string_generator(6, 20)):
    print(my_count, my_string)

输出：

0 RS9N3P
1 S0GDGR
2 ZNBLFV
3 96FF97
4 38JJZ3
5 Q3214A
6 VLWNK1
7 QMT05E
8 X1ZFP0
9 MZF442
10 10L9AZ
11 GE8HIQ
12 S7PA43
13 MVLXO9
14 YX7Y0G
15 GIIKPF
16 3KCUQA
17 XHIXFV
18 BJQ5VG
19 HQF01Q

如果字符串始终需要包含字母和数字，请使用以下命令：

#!/usr/bin/env python

from typing import Generator
from random import SystemRandom as RND
from string import ascii_uppercase, digits


def string_generator(size: int = 2, amount: int = 1) -> Generator[str, None, None]:
    """
    Return x random strings of a fixed length.

    :param size: string length, defaults to 1
    :type size: int, optional
    :param amount: amount of random strings to generate, defaults to 1
    :type amount: int, optional
    :yield: Yield composed random string if unique
    :rtype: Generator[str, None, None]
    """
    if size < 2:
        print(
            'Since the string must contain letters and numbers,',
            'its size must be at least two characters',
        )
        return
    CHARS = list(ascii_uppercase + digits)
    LIMIT = len(CHARS) ** size
    count, check, string = 0, set(), ''
    while LIMIT > count < amount:
        while 1:
            string = ''.join(RND().choices(CHARS, k=size))
            if not (string.isalpha() or string.isnumeric()):
                break
        if string not in check:
            check.add(string)
            yield string
            count += 1


for my_count, my_string in enumerate(string_generator(6, 20)):
    print(my_count, my_string)

输出：

0 5JIITL
1 3W7AI1
2 8QMO10
3 ETHAI8
4 BLFPP9
5 50X2CC
6 1LI8WA
7 39CKET
8 R4IM0E
9 Q3KHGS
10 65CBIU
11 XTRHO4
12 N2XIGO
13 06VFCW
14 VE9MJ8
15 A9ADHK
16 Y5ROJ0
17 OH7EJF
18 TQ709S
19 P0DDNJ