78 lines
1.5 KiB
Python
78 lines
1.5 KiB
Python
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# test scoping rules that involve a class
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# the inner A.method should be independent to the local function called method
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def test1():
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def method():
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pass
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class A:
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def method():
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pass
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print(hasattr(A, "method"))
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print(hasattr(A(), "method"))
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test1()
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# the inner A.method is a closure and overrides the local function called method
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def test2():
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def method():
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return "outer"
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class A:
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nonlocal method
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def method():
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return "inner"
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print(hasattr(A, "method"))
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print(hasattr(A(), "method"))
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return method() # this is actually A.method
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print(test2())
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# a class body will capture external variables by value (not by reference)
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def test3(x):
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class A:
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local = x
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x += 1
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return x, A.local
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print(test3(42))
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# assigning to a variable in a class will implicitly prevent it from closing over a variable
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def test4(global_):
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class A:
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local = global_ # fetches outer global_
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global_ = "global2" # creates class attribute
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global_ += 1 # updates local variable
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return global_, A.local, A.global_
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global_ = "global"
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print(test4(42), global_)
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# methods within a class can close over variables outside the class
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def test5(x):
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def closure():
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return x
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class A:
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def method():
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return x, closure()
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closure = lambda: x + 1 # change it after A has been created
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return A
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print(test5(42).method())
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