Is there any way I can get rid of required argument error?

Question

The problem is, if I define a function in python with 3 parameters and then I input only 2 parameters, I will get an error.

Can I define the function so if there is one parameter missing (user has given 2 inputs instead of 3), it will use a default value for that missing parameter such as 0?

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

If I use:

add = sum(1, 2)
print(add)

It will give me an error. Now I want to define the function so it will add the missing value as 0, but if I give all the 3 values, it will not use 0 as a default value.

https://stackoverflow.com/questions/9539921/how-do-i-create-a-python-function-with-optional-arguments/9539977#9539977 — lvzxy, Oct 07 '19 at 19:50
Possible duplicate of [How do I create a Python function with optional arguments?](https://stackoverflow.com/questions/9539921/how-do-i-create-a-python-function-with-optional-arguments) — CristiFati, Oct 07 '19 at 19:52
Start by not naming your function *sum*, you're shadowing the builtin one. — CristiFati, Oct 07 '19 at 19:52

score 3 · Answer 1 · answered Oct 07 '19 at 19:51

3

you can use default parameters:

def my_sum(a, b, c=0):
    return  a + b + c

answered Oct 07 '19 at 19:51

kederrac

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score 0 · Answer 2 · answered Oct 07 '19 at 19:53

When defining the defining a function if you set a value to a parameter, then you are tellign the function to use that value as default, except a value is specified. This means that by setting a=0,b=0,c=0 AS @Olvin Roght said, you will by default pass a 0 to those parameters (hence not affecting your sum) unless something else is specified.

Example:

def sum(a=0, b=0, c=0):
    return a+b+c

Output:

print(sum(a=1,b=2))
3 #1+2+0
print(sum(a=1,b=2,c=3))
6 #1+2+3
print(sum())
0 #0+0+0

Is there any way I can get rid of required argument error?

2 Answers2