将用户输入变量合并为一个变量。其中一个可能不是变量

Question

我正在制作密码生成器。如果用户在问题中输入 no，我该如何做到这一点。例如，没有大写。生成器 sill 可以不使用大写字母吗？

   print("hello, Welcome to Password Generator")
            length = int(input('Please enter the length of password: '))
            upperanswer = input("Would you like to use UpperCase? ")
            if upperanswer == "yes":
                    upper = string.ascii_uppercase
            loweranswer = input("Would you like to use LowerCase?")
            if loweranswer == "yes":
                    lower = string.ascii_lowercase
            numberanswer = input("Would you like to use Numbers?")
            if numberanswer == "yes":
                    numbers = string.digits
            specialanswer = input("Would you like to use Special Characters?")
            if specialanswer == "yes":
                    special = string.punctuation
            all = lower + upper + numbers + special
            temp = random.sample(all,length)
            password = "".join(temp)
            print(password)

Answer 1

此代码的问题是，如果您回答 yes 到 upper 以外的任何内容，则该变量将未定义。我建议扩展一个我称为characters 的字符串，这样无论用户回答什么，您都可以参考它。

#!/usr/bin/env python3
import string
import random
print("hello, Welcome to Password Generator")

characters = ""

length = int(input('Please enter the length of password: '))
upperanswer = input("Would you like to use UpperCase? ")
if upperanswer == "yes":
        characters += string.ascii_uppercase
loweranswer = input("Would you like to use LowerCase? ")
if loweranswer == "yes":
        characters += string.ascii_lowercase
numberanswer = input("Would you like to use Numbers? ")
if numberanswer == "yes":
        characters += string.digits
specialanswer = input("Would you like to use Special Characters? ")
if specialanswer == "yes":
        characters += string.punctuation

temp = random.sample(characters, length)
password = "".join(temp)
print(password)

结果：

hello, Welcome to Password Generator
Please enter the length of password: 10
Would you like to use UpperCase? no
Would you like to use LowerCase? yes
Would you like to use Numbers? no
Would you like to use Special Characters? yes
%-injo!&^e

Answer 2

只需在用户输入 no 时将字符串设置为空，方法是向每个 if 语句添加 else 语句，参见下面的代码。请注意，如果用户尝试为所有选项输入 no，这当然会失败，因为这样就没有可用的字符了

import random
import string

print("hello, Welcome to Password Generator")
length = int(input('Please enter the length of password: '))
upperanswer = input("Would you like to use UpperCase? ")
if upperanswer == "yes":
    upper = string.ascii_uppercase
else:
    upper = ""
loweranswer = input("Would you like to use LowerCase?")
if loweranswer == "yes":
    lower = string.ascii_lowercase
else:
    lower = ""
numberanswer = input("Would you like to use Numbers?")
if numberanswer == "yes":
    numbers = string.digits
else:
    numbers = ""
specialanswer = input("Would you like to use Special Characters?")
if specialanswer == "yes":
    special = string.punctuation
else:
    specialanswer = ""
all = lower + upper + numbers + special
temp = random.sample(all, length)
password = "".join(temp)
print(password)