Python 3 Try Except Error Handling With Missing Arguments in Function

Question

I am having trouble dealing with exceptions where the incorrect number of arguments are given when a function is called.

Here's a simplified example:

def func(arg1, arg2):
    return arg1 + arg2

func(46)

When the function is called without the correct number of arguments, the following error message is generated:

TypeError: func() missing 1 required positional argument: 'arg2'

I have tried to add a try, except to handle this exception, as follows, but it does not work:

def func(arg1, arg2):
    try:
        return arg1 + arg2
    except:
        return 'Incorrect input'

The function still generates the error message, rather than the 'Incorrect input' statement.

How can I have the function return the message 'Incorrect input' when the wrong number of arguments are given when the function is called?

Thanks

Why would you want that? The developer should be able to understand the given error message just fine. — luk2302, Sep 04 '21 at 07:44

score 0 · Answer 1 · answered Sep 04 '21 at 07:33

The exception happens upon the function call, before entering func so you did not manage to catch it:

def func(arg1, arg2):
        return arg1 + arg2

try:
    func(46)
except TypeError:
    print('Incorrect input')

Note the error message you received state it is 'TypeError' so you should catch only this kind of error.

1 Answers1