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Merge pull request #750 from xksteven/master
[python3/en] Added Boolean operators + lowered line lengths
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4b63f7bf38
@ -57,9 +57,17 @@ to Python 2.x. Look for another tour of Python 3 soon!
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# Enforce precedence with parentheses
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(1 + 3) * 2 # => 8
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# Boolean values are primitives
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True
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False
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# Boolean Operators
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+# Note "and" and "or" are case-sensitive
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+True and False #=> False
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+False or True #=> True
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+
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+# Note using Bool operators with ints
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+0 and 2 #=> 0
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+-5 or 0 #=> -5
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+0 == False #=> True
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+2 == True #=> False
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1 == True #=> True
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# negate with not
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not True # => False
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@ -61,6 +61,18 @@ False
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not True # => False
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not False # => True
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# Boolean Operators
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# Note "and" and "or" are case-sensitive
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True and False #=> False
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False or True #=> True
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# Note using Bool operators with ints
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0 and 2 #=> 0
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-5 or 0 #=> -5
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0 == False #=> True
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2 == True #=> False
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1 == True #=> True
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# Equality is ==
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1 == 1 # => True
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2 == 1 # => False
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@ -127,7 +139,8 @@ bool({}) #=> False
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# Python has a print function
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print("I'm Python. Nice to meet you!")
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# No need to declare variables before assigning to them. Convention is to use lower_case_with_underscores
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# No need to declare variables before assigning to them.
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# Convention is to use lower_case_with_underscores
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some_var = 5
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some_var # => 5
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@ -176,7 +189,8 @@ li[::-1] # => [3, 4, 2, 1]
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del li[2] # li is now [1, 2, 3]
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# You can add lists
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li + other_li # => [1, 2, 3, 4, 5, 6] - Note: values for li and for other_li are not modified.
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# Note: values for li and for other_li are not modified.
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li + other_li # => [1, 2, 3, 4, 5, 6]
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# Concatenate lists with "extend()"
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li.extend(other_li) # Now li is [1, 2, 3, 4, 5, 6]
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@ -215,14 +229,17 @@ filled_dict = {"one": 1, "two": 2, "three": 3}
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# Look up values with []
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filled_dict["one"] # => 1
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# Get all keys as a list with "keys()". We need to wrap the call in list() because we are getting back an iterable. We'll talk about those later.
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list(filled_dict.keys()) # => ["three", "two", "one"]
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# Get all keys as a list with "keys()".
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# We need to wrap the call in list() because we are getting back an iterable. We'll talk about those later.
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# Note - Dictionary key ordering is not guaranteed.
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# Your results might not match this exactly.
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list(filled_dict.keys()) # => ["three", "two", "one"]
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# Get all values as a list with "values()". Once again we need to wrap it in list() to get it out of the iterable.
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list(filled_dict.values()) # => [3, 2, 1]
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# Note - Same as above regarding key ordering.
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list(filled_dict.values()) # => [3, 2, 1]
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# Check for existence of keys in a dictionary with "in"
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"one" in filled_dict # => True
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@ -242,6 +259,10 @@ filled_dict.get("four", 4) # => 4
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filled_dict.setdefault("five", 5) # filled_dict["five"] is set to 5
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filled_dict.setdefault("five", 6) # filled_dict["five"] is still 5
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# Adding to a dictionary
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filled_dict.update({"four":4}) #=> {"one": 1, "two": 2, "three": 3, "four": 4}
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#filled_dict["four"] = 4 #another way to add to dict
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# Remove keys from a dictionary with del
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del filled_dict["one"] # Removes the key "one" from filled dict
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@ -458,6 +479,7 @@ map(add_10, [1, 2, 3]) # => [11, 12, 13]
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filter(lambda x: x > 5, [3, 4, 5, 6, 7]) # => [6, 7]
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# We can use list comprehensions for nice maps and filters
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# List comprehension stores the output as a list which can itself be a nested list
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[add_10(i) for i in [1, 2, 3]] # => [11, 12, 13]
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[x for x in [3, 4, 5, 6, 7] if x > 5] # => [6, 7]
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