python case: generate verification codes

# Design of a generating function specified length codes, codes composed of uppercase and lowercase letters and numbers

generate
English [dʒenəreɪt]
United States [dʒenəreɪt]
. V generated; cause;
[例句]The Employment Minister said the reforms would generate new jobs.
Minister of Labor said that the reform would bring new jobs.
[Other] third person singular: generates participle: generating
Past tense: generated past participle: generated

import random


def generate_code(code_len=4):
    """
    生成指定长度的验证码
    :param code_len: 验证码的默认长度为4
    :return: 由大小写字母和数字构成
    """
    all_chars = '123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
    last_char = len(all_chars) - 1  # 下标等于长度减去1
    code = ''
    for _ in range(code_len):
        index = random.randint(0, last_char)
        code += all_chars[index]
    return code


if __name__ == '__main__':
    print(generate_code())