Python 3.10.6：调用用户定义的 function 时出现语法错误和名称错误

Question

I'm using Python IDLE Shell 3.10.6, and this happens:

def math(x,y):
    return x*y
math(1,2)
SyntaxError: invalid syntax
math(1,2)
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    math(1,2)
NameError: name 'math' is not defined

Is this because Python 3.10.6 has a different syntax? I've tried the same thing in Jupyter notebook and it worked perfectly.

Can anyone help me out please? Thank you in advance!

Answer 1

This hasn't got anything to do with Python syntax, but quirks of the IDLE interactive shell.

In the interactive shell, you'll want to separate the definition of the function and the call into separate entries with an ENTER press, ie not so it reads

>>> def math(x,y):
    return x*y
math(1,2)
SyntaxError: invalid syntax

(as it's attempting to parse the function to contain a trailing, unindented line)

but instead so it reads

>>> def math(x,y):
    return x*y

>>> math(1, 2)
2