How can I change the "a" vaule use the patato function?-CodePudding

def patato(a):
    a  = 1
def tomato():
    a = 0 
    patato(a)
    print(a)
tomato()

How can I change the "a" vaule use the patato function?

CodePudding user response：

Assigning to the parameter variable doesn't affect the caller's variable, since variables are passed by value, not reference (in the case of mutable objects, the value is a reference to that object, but not a reference to the variable).

patato should return the new value, then you can assign it back to the variable.

def patato(a):
    return a   1

def tomato():
    a = 0
    a = patato(a)
    print(a)

tomato()

CodePudding user response：

Try this and see if you can understand it, or ask further questions:

def patato(a):
    a  = 1
    return a
    
def tomato():
    a = 0 
    return patato(a)
    
print(tomato())   # 1