1class C:
2    def f():
3        pass
4
5# del a class attribute
6
7del C.f
8try:
9    print(C.x)
10except AttributeError:
11    print("AttributeError")
12try:
13    del C.f
14except AttributeError:
15    print("AttributeError")
16
17# del an instance attribute
18
19c = C()
20
21c.x = 1
22print(c.x)
23
24del c.x
25try:
26    print(c.x)
27except AttributeError:
28    print("AttributeError")
29try:
30    del c.x
31except AttributeError:
32    print("AttributeError")
33
34# try to del an attribute of a built-in class
35try:
36    del int.to_bytes
37except (AttributeError, TypeError):
38    # uPy raises AttributeError, CPython raises TypeError
39    print('AttributeError/TypeError')
40