47 lines
1.0 KiB
Python
47 lines
1.0 KiB
Python
# final_considerations.py
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>>> a = 1000000
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>>> b = 1000000
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>>> id(a) == id(b)
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False
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>>> a = 5
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>>> b = 5
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>>> id(a) == id(b)
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True
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# how to choose data structures
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# example customer objects
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customer1 = {'id': 'abc123', 'full_name': 'Master Yoda'}
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customer2 = {'id': 'def456', 'full_name': 'Obi-Wan Kenobi'}
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customer3 = {'id': 'ghi789', 'full_name': 'Anakin Skywalker'}
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# collect them in a tuple
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customers = (customer1, customer2, customer3)
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# or collect them in a list
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customers = [customer1, customer2, customer3]
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# or maybe within a dictionary, they have a unique id after all
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customers = {
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'abc123': customer1,
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'def456': customer2,
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'ghi789': customer3,
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}
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# negative indexing
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>>> a = list(range(10)) # `a` has 10 elements. Last one is 9.
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>>> a
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[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
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>>> len(a) # its length is 10 elements
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10
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>>> a[len(a) - 1] # position of last one is len(a) - 1
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9
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>>> a[-1] # but we don't need len(a)! Python rocks!
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9
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>>> a[-2] # equivalent to len(a) - 2
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8
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>>> a[-3] # equivalent to len(a) - 3
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7
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