Function's arguments

Question

hey guys, i have got a little problem with this part of a code: it has to change the default value of an argument of a function

https://code.sololearn.com/cNNkMA0asY22/?ref=app

the commented part doesn't work, instead the code below run correctly
is it an 'elegant' solution? is there a better way to make this code run correctly?

Answer 1

Hello !

The principle of a default parameter is that it won't change and is used when no parameter is provided on function call.

So in your example, set the default parameter to a value in the function definition:

def f(val=2)

then when you call
f() -> val equals 2.

If you need to set val to another value, call the function with a parameter :

f(val=5)

Another comment, global variable are often not recommended. Your f() function should instead return a value. Like this :

def f(val=2):
print(val)
return val

yourval = f()

# This will print 2 and set yourval to 2

yourval = f(5)

# This will print 5 and set yourval to 5

Answer 2

thank you @Burrich , i used this method because i have to call different functions imported from an external file
all these functions refer to an object which change during the program
to avoid re-writing the reference of the object in each functions i tried to use this ploy
the other solution to avoid using global variable could be to creating a class..