Python中的input()函数可以动态检测输入的数据类型吗? [英] Can the input() function in Python dynamically detect the input's data type?

问题描述

因此，我使用Python 3.7制作了控制台应用程序；很大程度上取决于输入(wowz).

应用程序的功能是在两个整数变量的值之间交换".那不是问题所在，问题在于，当我尝试通过使用几个"if语句"检查输入的数据类型来验证用户的输入时，无论用户使用" input()"功能进行输入；输入的数据类型将始终定义为"

The application's function is to "swap" between two integer variables' values. And that is not where the problem is at, the problem is when I try to validate the user's input by checking the data-type for the input using a couple "if statements", and no matter what the user inputs using the "input()" function; the input's data-type will always be defined as ""

我只希望这小块ART动态运行.(我希望input()函数动态检测输入的数据类型并将其分配给变量?plsss)

I just want this little piece of ART to run dynamically. (I want the input() function to dynamically detect the data-type of the input and assign it to the variable? plsss)

P.S .:我什么也没尝试，因为我发现所有的东西都是无用的.我猜.(告诉我使用 int()函数，例如:{

P.S.: I didn't try anything, since all I found was useless; I guess. (tells me to use the int() function, e.g.: {

# Works just fine when input is fully composed of integral numbers. 
a = int(input("Enter an integer as a value for A: "))

} (下面第5行的编辑)

我不想使用 int()函数；如果用户输入的字符串不完全由整数组成，则可能会引起很多问题.(ValueError)

I don't want to use the int() function; since it'll cause a pile of problems, if the user's input was a string that was not fully composed of integral numbers. (ValueError)

def swap(x, y):
    return y, x
aValid = 1
bValid = 1
a = input("Enter an integer as a value for A: ")
if (str(type(a)) != "<class 'int'>"):
    print("Please take us seriously, we're watching you.\n")
    aValid = 0
    while (aValid == 0):
        a = input("Enter an integer as a  value for A: ")
        if str(type(a)) != "<class 'int'>":
            print("Please take us seriously, we're watching you.\n")
            aValid = 0
        else:
            aValid = 1

# ! To be worked on:

b = input("Now, Please enter the value for B: ")
print("A = " , a)
print ("B = ", b)

a, b = swap(a, b)

print("Now:\nA = ", a)
print("B = ", b)

我希望 Python 3.7(32位)中的 input()函数可以动态检测输入的数据类型并将其分配变量以及输入本身.

I expected the input() function in Python 3.7 (32bit) to dynamically detect the data-type of the input and assign it to the variable along with the input itself.

但是实际上发生的是，它总是将输入的数据类型分配为<类'str'>" ；(<和>之前没有空格)，这会使程序陷入无限循环，这让我很头疼；我的愚蠢.

But what actually happens is that it always assigns the input's data-type as "< class 'str' >"; (no spaces after < and before >, ) which causes the program to go into an infinite loop, and it is giving me a headache; my stupidity.

推荐答案

因此，在python 2中， input()函数将检测用户输入的类型.但是，在python3中， input()指的是python 2中的 raw_input().为了动态检测类型，可以使用 ast ，特别是 ast.literal_eval .

So, in python 2 the input() function would detect the type of the user's input. However, in python3 input() refers to raw_input() in python 2. In order to dynamically detect the type, you can use the ast, specifically ast.literal_eval.

您可能会编写如下自己的输入函数:

You could potentially write your own input function as follows:

import ast

def input_detect(s):
    return ast.literal_eval(input(s))

，然后您的代码将如下所示:

and then your code would look like:

import ast

def input_detect(s):
    return ast.literal_eval(input(s))

def swap(x, y):
    return y, x
aValid = 1
bValid = 1
a = input_detect("Enter an integer as a value for A: ")
if (str(type(a)) != "<class 'int'>"):
    print("Please take us seriously, we're watching you.\n")
    aValid = 0
    while (aValid == 0):
        a = input_detect("Enter an integer as a  value for A: ")
        if str(type(a)) != "<class 'int'>":
            print("Please take us seriously, we're watching you.\n")
            aValid = 0
        else:
            aValid = 1

# ! To be worked on:

b = input_detect("Now, Please enter the value for B: ")
print("A = " , a)
print ("B = ", b)

a, b = swap(a, b)

print("Now:\nA = ", a)
print("B = ", b)

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