21 lines
1.8 KiB
Python
21 lines
1.8 KiB
Python
collection = [0, '1'] # Lists are mutable (editable) and can be sorted in place
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x = collection[0] # accessing an item (which happens to be a numeric 0 (zero)
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collection.append(2) # adding something to the end of the list
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collection.insert(0, '-1') # inserting a value into the beginning
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y = collection[0] # now returns a string of "-1"
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collection.extend([2,'3']) # same as [collection.append(i) for i in [2,'3']] ... but faster
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collection += [2,'3'] # same as previous line
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collection[2:6] # a "slice" (collection of the list elements from the third up to but not including the sixth)
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len(collection) # get the length of (number of elements in) the collection
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collection = (0, 1) # Tuples are immutable (not editable)
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collection[:] # ... slices work on these too; and this is equivalent to collection[0:len(collection)]
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collection[-4:-1] # negative slices count from the end of the string
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collection[::2] # slices can also specify a stride --- this returns all even elements of the collection
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collection="some string" # strings are treated as sequences of characters
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x = collection[::-1] # slice with negative step returns reversed sequence (string in this case).
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collection[::2] == "some string"[::2] # True, literal objects don't need to be bound to name/variable to access slices or object methods
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collection.__getitem__(slice(0,len(collection),2)) # same as previous expressions.
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collection = {0: "zero", 1: "one"} # Dictionaries (Hash)
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collection['zero'] = 2 # Dictionary members accessed using same syntax as list/array indexes.
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collection = set([0, '1']) # sets (Hash)
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