为什么会出现此语法错误：关键字不能为表达式

Question

def multiply():
    number_1 = int (input ("Please insert the first number for multiplication:"))
    number_2 = int (input ("Please insert the second number for multiplication:"))
    result = str (number_1*number_2)
    return print (number_1*number_2=result)
multiply()

I am getting the Following error when trying to execute the following function.

    return print (number_1*number_2=result)               
                 ^
SyntaxError: keyword can't be an expression

Answer 1

You are defining a keyword argument by using = :

...(number_1*number_2=result)
                     ^

That makes everything before the = a Python expression, namely number_1 * number_2 . Python doesn't allow this.

If you wanted to print out a nicely formatted expression, you'll have to use separate string arguments:

print(number_1, '*', number_2, '=', result)

Python writes out separate arguments with a space to separate them (but you can use sep='...' to set a different string to separate them, including the empty string to have no separation at all).

Note that you don't actually have to convert result to a string here, the print() function converts all arguments to strings before writing them to the console.

You could also learn about Python string formatting , which gives you a bit more control over the whitespace handling, as well as alignment end value formatting, for example.

The following would print out your numbers and the result as part of a format string with the same amount of spaces:

print('{} * {} = {}'.format(number_1, number_2, result))

Each {} placeholder is then filled with the next argument you passed into the str.format() method . You can remove the spaces here too if you wanted to.

Last, but not least, the print() function always returns None . You don't have to return that from your function, remove the return . Your actual use of the multiply function doesn't use the returned value anyway:

def multiply():
    number_1 = int(input("Please insert the first number for multiplication:"))
    number_2 = int(input("Please insert the second number for multiplication:"))
    result = number_1 * number_2
    print(number_1, '*', number_2, '=', result)

multiply()

Answer 2

Why am I getting this syntax error: keyword can't be an expression

Because what you write in parentheses after a function name (including print in python3) are arguments of the function. Any argument written in the form keyword=value is a keyword argument . You cannot use an expression (here a product) as a keyword.

Answer 3

I assume you want output like

number_1*number2 = 6

The first part of this is some fixed text you want printed. Thus you need to put in in a string and print that. You can print multiple things like print(a, b) . This should be enough for you to figure out

Answer 4

You have two issues:

You are writing an expression inside a print statement. Instead you want to make a formatted string and substitute the values into the string:

print("%d*%d=%s" % (number_1, number_2, result))

Secondly, you don't need to return it.