Problem/bug with class definition inside function definition

[Alexey Muranov]

I have discovered the following bug or problem: it looks like i am 
forced to choose different names for class attributes and function 
arguments, and i see no workaround.  Am i missing some special syntax 
feature ?

Alexey.

---
x = 42

class C1:
    y = x  # Works

class C2:
    x = x  # Works

# ---
def f1(a):
    class D:
        b = a  # Works
    return D

def f2(a):
    class D:
        a = a  # Does not work <<<<<
    return D

def f3(a):
    class D:
        nonlocal a
        a = a  # Does not work either <<<<<
    return D

# ---
def g1(a):
    def h():
        b = a  # Works
        return b
    return h

def g2(a):
    def h():
        a = a  # Does not work (as expected)
        return a
    return h

def g3(a):
    def h():
        nonlocal a
        a = a  # Works
        return a
    return h

# ---
if __name__ == "__main__":
    assert C1.y == 42
    assert C2.x == 42

    assert f1(13).b == 13

    try:
        f2(13)  # NameError
    except NameError:
        pass
    except Exception as e:
        raise Exception( 'Unexpected exception raised: '
                         '{}'.format(type(e).__name__) )
    else:
        raise Exception('No exception')

    try:
        f3(13).a  # AttributeError
    except AttributeError:
        pass
    except Exception as e:
        raise Exception( 'Unexpected exception raised: '
                         '{}'.format(type(e).__name__) )
    else:
        raise Exception('No exception')

    assert g1(13)() == 13

    try:
        g2(13)()  # UnboundLocalError
    except UnboundLocalError:
        pass
    except Exception as e:
        raise Exception( 'Unexpected exception raised: '
                         '{}'.format(type(e).__name__) )
    else:
        raise Exception('No exception')

    assert g3(13)() == 13