Normal arguments vs. keyword arguments

Question

How are \"keyword arguments\" different from regular arguments? Can\'t all arguments be passed as name=value instead of using positional syntax?

Answer 1

Using Python 3 you can have both required and non-required keyword arguments:

---

Optional: (default value defined for param 'b')

def func1(a, *, b=42):
    ...
func1(value_for_a) # b is optional and will default to 42

---

Required (no default value defined for param 'b'):

def func2(a, *, b):
    ... 
func2(value_for_a, b=21) # b is set to 21 by the function call
func2(value_for_a) # ERROR: missing 1 required keyword-only argument: 'b'`

This can help in cases where you have many similar arguments next to each other especially if they are of the same type, in that case I prefer using named arguments or I create a custom class if arguments belong together.