我在 python 中单个字符的数据类型上苦苦挣扎。 如果它是一个字符串，那么比较应该是字符串 function

Question

I am looking to add two numbers by accepting the response like this 12 + 56 Then I want to print 68 as output at the bottom of 56..it's showing some problems

def sum(a, b):
    return (a + b)


def sub(a, b):
    return (a - b)


def mul(a, b):
    return (a*b)


def div(a, b):
    return (a / b)


x - int(input(""))
z = str(input(""))
y = int(input(""))
if (z == '+'):
    print(sum(x, y))
elif (z == '-'):
    print(sub(x, y))
elif (z == '*'):
    print(mul(x, y))
else:
    print(div(x, y))

Answer 1

Um I have read the comment and try to summarise it here:)?

• x = int(input("")) use = instead of - to declare a variable and I think this is a typo?

• s is not defined to sum to number we can directly use the sum function, in my opinion, no need to create a function for it: eg

x = input('')
y = input('')
print(sum([int(x), int(y)]))

full code ( changed ):

def sum(a, b):
    return (a + b)


def sub(a, b):
    return (a - b)


def mul(a, b):
    return (a*b)


def div(a, b):
    return (a / b)


x = int(input("number : "))  # x - int(input(""))  -->  x = int(input(""))  # typo i think
z = str(input("operator : "))
y = int(input("number : "))

'''
I change the x y z here : how to handle empty input
one of the way is using the if else statement
if x y z is empty --> nothing is done :

num1 = input("number : ")  # and I prefer meaningful variable names : )
operator = input("operator : ")
num2 = input("number : ")

if num1.strip() == '' or num2.strip() == '':
    print('error message')
'''
'''
or you can also make a function to recur it :

def askInput():
    num1 = input("number : ")
    operator = input("operator : ")
    num2 = input("number : ")

    if num1.strip() == '' or num2.strip() == '':
        print("error")
        askInput()

    return num1, operator, num2

x, y, z = askInput()
print(x, y, z)  # just to test if it works , you can delete it in you code : )
... # add sub mul div function here
'''

if (z == '+'):
    print(sum(x, y))  # s is not defined --> i think it should be the function  sum()  right ?

    # but  sum  is already a python built-in stuff ( idk what it call sry )  so not need to
    # write a function for it i think
    
elif (z == '-'):
    print(sub(x, y))
    
elif (z == '*'):  # <-- i think it would be clear that  z == '*'  ?
    print(mul(x, y))
    
else:
    print(div(x, y))