python代码实现base64加解密算法

import base64
def main():
    while True:
        print('输入1表示base64加密，输入数字2表示base64解密，输入0退出！')
        choice = eval(input())
        if choice == 1:
            a = input('请输入需要加密的字符串：')
            a = bytes(a,encoding = 'utf-8')
            a = base64.b64encode(a)
            a = str(a,encoding = 'utf-8')
            print(a)
        elif choice == 2:
            a = input('请输入需要解密的字符串：')
            a = bytes(a, encoding='utf-8')
            a = base64.b64decode(a)
            a = str(a, encoding='utf-8')
            print(a)
        elif choice == 0:
            break
        else:
            print('请输入正确的数值！')
            continue
if __name__ == '__main__':
    main()