如何忽略在python中接受多个参数的函数中的字符串？

Question

I'm trying to answer a python programming question:

Write a function operate_nums that computes the product of all other input arguments and returns its negative if the keyword argument negate (default False ) is True or just the product if negate is False . The function should ignore non-numeric arguments.

So far I have the following code:

def operate_nums(*args):
     product = 1
     negate = True

     for i in args:
         product = product * i

     if negate == True:
         return product * -1
     return product

If I input a set of numbers and strings in my argument, how will code it so that my code ignores the strings?

Answer 1

Use isinstance that lets you check the type of your variable. As pointed in one of the comments by @DarrylG, you can use Number as an indicator whether an argument is the one you want to multiply by

from numbers import Number

def operate_nums(*args, negate=False):
    product = 1

    for arg in args:
        if isinstance(arg, Number): # check if the argument is numeric
            product = product * arg

    if negate == True:
            return product * -1

    return product