Python 函数从另一个函数调用变量。 但为什么？

Question

I know this one is pretty duplicated however:

def func1():
    a = [1,2,3,4,5]
    return a

def func2():
    b = func1()
    print(b.a[0])

func2()

AttributeError: 'list' object has no attribute 'a'

I WANT TO use '.' dot function(syntax) to access variables declared in other functions like :

print(b.a[0])
or
print(b.a)

should print out:

1
or
[1,2,3,4,5]

Wouldn't it make things so much easier?

And I know this can be done by using class or many other ways too.

But why won't it work this way? Are there any 'must' reason(s) behind this way of access? Will it make Python vulnerable? or will it make python unstable?

I wasn't able to find a perfect, concise, clear, accurate explanation for this accessing issue.

Many Thanks.

---

to be more accurate for @Goyo

def func():
    a = [1,2,3,4,5]

def func2():
    b = func()
    b.a[0] = "Not Working"
    print(b)

func2()

or

def func3():
    from . import func
    b = func()
    b.a[0] = 'Not working either'
    print(b)

func3()

I just feel it is more instinctive way of writing codes. Maybe it is just me.

Answer 1

You are mistaking class variables with functions variables

# This a Class
class MyFunctions():
    def __init__(self):
        pass
    # This is a function of the class
    def func1():
        a = [1, 2, 3, 4, 5]
        return a

# This is a Procedure, it is not function because it returns Nothing or None
def func2():

    b = MyFunctions.func1()
    print(b[0])

    # a variable of the class
    MyFunctions.func1.a = 3
    f = MyFunctions.func1.a
    print(f)

func2()

Answer 2

It's because you didn't say return in the func1 function, so you should do:

def func1():
    a = [1,2,3,4,5]
    return a

def func2():
    b = func1()
    print(b[0])

Answer 3

A function (in your case a procedure since it does not return anything) is a treatment on data, not a data holder like an object or a structure. When you write b = func() you expect to get the result of func(). You don't have to know what happens in func. a in your function is an internal variable that might be garbage collected at the end of the function (no one referencing it)