Add examples for weird things about python

2024/weird_things/booleans_subclassing_integers.py

@@ -0,0 +1,12 @@
+def main() -> None:
+    if 1:
+        print("1 is True")
+
+    print(1 == True)
+    print(0 == False)
+    print(1 + True)
+    print(True + True)
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/default_empty_list.py

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+def append_to_list[T](value: T, my_list: list[T] = []) -> list[T]:
+    my_list.append(value)
+    return my_list
+
+
+def main() -> None:
+    # First call
+    result1 = append_to_list(1)
+    print(result1)  # Output: [1]
+
+    # Second call
+    result2 = append_to_list(2)
+    print(result2)  # Output: [1, 2]
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/delayed_printing.py

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+import time
+
+
+def main() -> None:
+    print("Hello world", end="_")
+    time.sleep(3)
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/for_else_clause.py

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+def check_element_existence[T](data: list[T], to_find: T) -> None:
+    for num in data:
+        if num == to_find:
+            print("Exists!")
+            break
+    else:
+        print("Does not exist")
+
+
+def main() -> None:
+    data = [1, 2, 3, 4, 5]
+    check_element_existence(data, 4)
+    check_element_existence(data, -1)
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/function_attribute_mutation.py

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+def timer():
+    pass
+
+
+def main() -> None:
+    timer.counter = 0
+    timer.counter += 1
+    print(timer.counter)  # Output: 1
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/integer_caching.py

@@ -0,0 +1,12 @@
+def main() -> None:
+    a = 256
+    b = 256
+    print(a is b)  # Output: True
+
+    c = 257
+    d = 257
+    print(c is d)  # Output: False
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/mutating_immutable_struct.md

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+# Run the following in the Python console
+# Expected bevahior! data is (1,2)
+data = (1, 2)
+data[0] += 1 # Returns an error
+data # Is (1,2)
+
+# Not expected! data is ([1, 3], 2)
+data = ([1],2)
+data[0] += [3]
+data 

2024/weird_things/pyproject.toml

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+[tool.poetry]
+name = "weird-things"
+version = "0.1.0"
+description = ""
+authors = ["Andreas Bergman <[email protected]>"]
+readme = "README.md"
+
+[tool.poetry.dependencies]
+python = "^3.11"
+
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"

2024/weird_things/reference_inconsistency.py

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+def main() -> None:
+    a = [1, 2, 3]
+    b = a  # b is now a reference to a
+    a += [4]
+    print(b)  # Output: [1, 2, 3, 4]
+
+    s = "hello"
+    t = s  # t is now a reference to s
+    s += " world"
+    print(t)  # Output: "hello"
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/space_invader_operator.py

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+def main() -> None:
+    a = 420
+    a -=- 1
+    print(a)
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/variable_global_scope_a.py

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+def main() -> None:
+    for x in range(7):
+        if x == 6:
+            print(x, ": for x inside loop")
+    print(x, ": x in global/scope")
+
+
+if __name__ == "__main__":
+    main()

2024/weird_things/variable_global_scope_b.py

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+def main() -> None:
+    [x for x in range(7) if x == 6 and print(f"{x}: for x inside loop")]
+    print(x, ": x in global")  # will return an error
+
+
+if __name__ == "__main__":
+    main()