从 python 中的 function 外部重新分配 function 变量

Question

I'm new to coding. I'm trying to access a function variable from outside the function.

def calculate_age():
    age =10

my_age=calculate_age ()
my_age.calculate_age.age=20

Error

Traceback (most recent call last):
  File "main.py", line 15, in <module>
    my_age.calculate_age.age=20
AttributeError: 'NoneType' object has no attribute 'calculate_age'

Answer 1

I am writing an answer as I can't comment yet. Functions should have a "return" statement, which passes on the output of the function. In your case you'd need to have it like this:

def calculate_age():
    age =10  # ideally have a calculation here
    return age

Have a look on this page for how functions work.

Answer 2

You can't access that variable outside of that function. Look at this:

def calculate_age():
    age = 10  # this variable is local to the function. you can't access it anywhere else.
    return age


my_age = calculate_age()  # set a variable outside the function.
print(my_age)
# prints 10

my_age = 20 # change the variable
print(my_age)
# prints 20

This is called "scope" and you can read about it here .

Answer 3

Like other users already mentioned, you can't do that using a function. However you can get this behavior using an object or in python called a class. extra info here

As an example, you could create a class Person.

class Person():
    age = 10
    height = 1.5
    lan = "Eng"

paul = Person()

Now you can use the instance of Person called "paul" to do.

paul.age #returns 10
paul.age = 20
paul.age #returns 20