如何增加列表中每个项目/元素的值？

Question

我目前正在尝试制作凯撒解码器,所以我试图找出如何获取用户输入的移位值,并使用该输入来移动列表中的每个项目.但每次我尝试,它只是一直给我一个错误.

例如:

word 在ASCII中将是:

[119, 111, 114, 100]

如果转移的给定输入是2,我希望列表是:

[121, 113, 116, 102]

请帮忙.这是我的第一次编程和这个凯撒解码器让我发疯:(

这就是我到目前为止所拥有的

import string

def main():

    inString = raw_input("Please enter the word to be "
                        "translated: ")
    key = raw_input("What is the key value or the shift? ")

    toConv = [ord(i) for i in inString] # now want to shift it by key value
    #toConv = [x+key for x in toConv]   # this is not working, error gives 'cannot add int and str

    print "This is toConv", toConv

此外,如果你们不使用任何花哨的功能,将会很有帮助.相反,请使用现有代码.我是新手.

Answer 1

raw_input返回一个字符串对象并ord返回一个整数.此外,正如错误消息所述,您无法将字符串和整数与+以下内容一起添加:

>>> 'a' + 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: cannot concatenate 'str' and 'int' objects
>>>

但是,这正是您在此尝试做的事情:

toConv = [x+key for x in toConv]

在上面的代码中,x将是一个整数(因为toConv是一个整数列表)并且key将是一个字符串(因为你曾经raw_input得到它的值).

您只需将输入转换为整数即可解决问题:

key = int(raw_input("What is the key value or the shift? "))

之后,您的列表理解将按预期工作.

以下是演示:

>>> def main():
...     inString = raw_input("Please enter the word to be "
...                         "translated: ")
...     # Make the input an integer
...     key = int(raw_input("What is the key value or the shift? "))
...     toConv = [ord(i) for i in inString]
...     toConv = [x+key for x in toConv]
...     print "This is toConv", toConv
...
>>> main()
Please enter the word to be translated: word
What is the key value or the shift? 2
This is toConv [121, 113, 116, 102]
>>>