From 9b6d84309c8b554ab87b19e27eadbe550d5204a6 Mon Sep 17 00:00:00 2001 From: Keith Miyake Date: Thu, 19 Oct 2017 22:26:32 -0700 Subject: [python3/en] Add single inheritance section --- python3.html.markdown | 128 +++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 111 insertions(+), 17 deletions(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index 5aa61b65..e02aed43 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -669,7 +669,7 @@ class Human: # An instance method. All methods take "self" as the first argument def say(self, msg): - print ("{name}: {message}".format(name=self.name, message=msg)) + print("{name}: {message}".format(name=self.name, message=msg)) # Another instance method def sing(self): @@ -740,7 +740,101 @@ if __name__ == '__main__': #################################################### -## 6.1 Multiple Inheritance +## 6.1 Inheritance +#################################################### + +# Inheritance allows new child classes to be defined that inherit methods and +# variables from their parent class. + +# Using the Human class defined above as the base or parent class, we can +# define a child class, Superhero, which inherits the class variables like +# "species", "name", and "age", as well as methods, like "sing" and "grunt" +# from the Human class, but can also have its own unique properties. + +# To take advantage of modularization by file you could place the classes above in their own files, +# say, human.py + +# To import functions from other files use the following format +# from "filename-without-extension" import "function-or-class" + +from human import Human + + +# Specify the parent class(es) as parameters to the class definition +class Superhero(Human): + + # If the child class should inherit all of the parent's definitions without + # any modifications, you can just use the "pass" keyword (and nothing else) + # but in this case it is commented out to allow for a unique child class: + # pass + + # Child classes can override their parents' attributes + species = 'Superhuman' + + # Children automatically inherit their parent class's constructor including + # its arguments, but can also define additional arguments or definitions + # and override its methods such as the class constructor. + # This constructor inherits the "name" argument from the "Human" class and + # adds the "superpower" and "movie" arguments: + def __init__(self, name, movie=False, + superpowers=["super strength", "bulletproofing"]): + + # add additional class attributes: + self.fictional = True + self.movie = movie + self.superpowers = superpowers + + # The "super" function lets you access the parent class's methods + # that are overwritten by the child, in this case, the __init__ method. + # This calls the parent class constructor: + super().__init__(name) + + # overload the sing method + def sing(self): + return 'Dun, dun, DUN!' + + # add an additional class method + def boast(self): + for power in self.superpowers: + print("I wield the power of {pow}!".format(pow=power)) + + +if __name__ == '__main__': + sup = Superhero(name="Tick") + + # Instance type checks + if isinstance(sup, Human): + print('I am human') + if type(sup) is Superhero: + print('I am a superhero') + + # Get the Method Resolution search Order used by both getattr() and super() + # This attribute is dynamic and can be updated + print(Superhero.__mro__) # => (, + # => , ) + + # Calls parent method but uses its own class attribute + print(sup.get_species()) # => Superhero + + # Calls overloaded method + print(sup.sing()) # => Dun, dun, DUN! + + # Calls method from Human + sup.say('Spoon') # => Tick: Spoon + + # Call method that exists only in Superhero + sup.boast() # => I wield the power of super strength! + # => I wield the power of bulletproofing! + + # Inherited class attribute + sup.age = 31 + print(sup.age) # => 31 + + # Attribute that only exists within Superhero + print('Am I Oscar eligible? ' + str(sup.movie)) + +#################################################### +## 6.2 Multiple Inheritance #################################################### # Another class definition @@ -766,20 +860,16 @@ if __name__ == '__main__': print(b.fly) # To take advantage of modularization by file you could place the classes above in their own files, -# say, human.py and bat.py +# say, superhero.py and bat.py # To import functions from other files use the following format # from "filename-without-extension" import "function-or-class" - # superhero.py -from human import Human +from superhero import Superhero from bat import Bat -# Batman inherits from both Human and Bat -class Batman(Human, Bat): - - # Batman has its own value for the species class attribute - species = 'Superhero' +# Batman inherits from both Superhero and Bat +class Batman(Superhero, Bat): def __init__(self, *args, **kwargs): # Typically to inherit attributes you have to call super: @@ -789,7 +879,8 @@ class Batman(Human, Bat): # So instead we explicitly call __init__ for all ancestors. # The use of *args and **kwargs allows for a clean way to pass arguments, # with each parent "peeling a layer of the onion". - Human.__init__(self, 'anonymous', *args, **kwargs) + Superhero.__init__(self, 'anonymous', movie=True, + superpowers=['Wealthy'], *args, **kwargs) Bat.__init__(self, *args, can_fly=False, **kwargs) # override the value for the name attribute self.name = 'Sad Affleck' @@ -802,8 +893,8 @@ if __name__ == '__main__': sup = Batman() # Instance type checks - if isinstance(sup, Human): - print('I am human') + if isinstance(sup, Superhero): + print('I am a superhero) if isinstance(sup, Bat): print('I am bat') if type(sup) is Batman: @@ -811,10 +902,13 @@ if __name__ == '__main__': # Get the Method Resolution search Order used by both getattr() and super(). # This attribute is dynamic and can be updated - print(Batman.__mro__) # => (, , , ) + print(Batman.__mro__) # => (, + # => , + # => , + # => , ) # Calls parent method but uses its own class attribute - print(sup.get_species()) # => Superhero + print(sup.get_species()) # => Superhuman # Calls overloaded method print(sup.sing()) # => nan nan nan nan nan batman! @@ -827,10 +921,10 @@ if __name__ == '__main__': # Inherited class attribute sup.age = 100 - print(sup.age) + print(sup.age) # => 100 # Inherited attribute from 2nd ancestor whose default value was overridden. - print('Can I fly? ' + str(sup.fly)) + print('Can I fly? ' + str(sup.fly)) # => Can I fly? False -- cgit v1.2.3 From 55efb934b8d7f2034020d17e331f02b852952012 Mon Sep 17 00:00:00 2001 From: Keith Miyake Date: Mon, 23 Oct 2017 15:11:13 -0700 Subject: python3/en cleanup for single inheritance merge --- python3.html.markdown | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index e02aed43..37987582 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -785,7 +785,7 @@ class Superhero(Human): self.superpowers = superpowers # The "super" function lets you access the parent class's methods - # that are overwritten by the child, in this case, the __init__ method. + # that are overridden by the child, in this case, the __init__ method. # This calls the parent class constructor: super().__init__(name) @@ -814,7 +814,7 @@ if __name__ == '__main__': # => , ) # Calls parent method but uses its own class attribute - print(sup.get_species()) # => Superhero + print(sup.get_species()) # => Superhuman # Calls overloaded method print(sup.sing()) # => Dun, dun, DUN! @@ -838,6 +838,7 @@ if __name__ == '__main__': #################################################### # Another class definition +# bat.py class Bat: species = 'Baty' @@ -859,16 +860,13 @@ if __name__ == '__main__': print(b.say('hello')) print(b.fly) -# To take advantage of modularization by file you could place the classes above in their own files, -# say, superhero.py and bat.py -# To import functions from other files use the following format -# from "filename-without-extension" import "function-or-class" +# And yet another class definition that inherits from Superhero and Bat # superhero.py from superhero import Superhero from bat import Bat -# Batman inherits from both Superhero and Bat +# Define Batman as a child that inherits from both Superhero and Bat class Batman(Superhero, Bat): def __init__(self, *args, **kwargs): @@ -892,14 +890,6 @@ class Batman(Superhero, Bat): if __name__ == '__main__': sup = Batman() - # Instance type checks - if isinstance(sup, Superhero): - print('I am a superhero) - if isinstance(sup, Bat): - print('I am bat') - if type(sup) is Batman: - print('I am Batman') - # Get the Method Resolution search Order used by both getattr() and super(). # This attribute is dynamic and can be updated print(Batman.__mro__) # => (, -- cgit v1.2.3 From 3386171160dd7fc3e4e6e9aaf2d5abfebdb38d6f Mon Sep 17 00:00:00 2001 From: Aswin Sanakan Date: Tue, 5 Dec 2017 12:24:43 +0530 Subject: Fix omitting in list and clarified comments --- python3.html.markdown | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index 37987582..153384de 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -209,9 +209,9 @@ li[4] # Raises an IndexError # The start index is included, the end index is not # (It's a closed/open range for you mathy types.) li[1:3] # => [2, 4] -# Omit the end +# Omit the beginning and return the list li[2:] # => [4, 3] -# Omit the beginning +# Omit the end and return the list li[:3] # => [1, 2, 4] # Select every second entry li[::2] # =>[1, 4] -- cgit v1.2.3 From 213019c689323af7f5c531fb156c34abe8771960 Mon Sep 17 00:00:00 2001 From: Rommel Martinez Date: Sat, 3 Feb 2018 18:08:24 +0800 Subject: [python3/en]: fix typo --- python3.html.markdown | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index 37987582..864228e4 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -6,6 +6,7 @@ contributors: - ["Andre Polykanine", "https://github.com/Oire"] - ["Zachary Ferguson", "http://github.com/zfergus2"] - ["evuez", "http://github.com/evuez"] + - ["Rommel Martinez", "https://ebzzry.io"] filename: learnpython3.py --- @@ -546,9 +547,9 @@ all_the_args(1, 2, a=3, b=4) prints: # Use * to expand tuples and use ** to expand kwargs. args = (1, 2, 3, 4) kwargs = {"a": 3, "b": 4} -all_the_args(*args) # equivalent to foo(1, 2, 3, 4) -all_the_args(**kwargs) # equivalent to foo(a=3, b=4) -all_the_args(*args, **kwargs) # equivalent to foo(1, 2, 3, 4, a=3, b=4) +all_the_args(*args) # equivalent to all_the_args(1, 2, 3, 4) +all_the_args(**kwargs) # equivalent to all_the_args(a=3, b=4) +all_the_args(*args, **kwargs) # equivalent to all_the_args(1, 2, 3, 4, a=3, b=4) # Returning multiple values (with tuple assignments) def swap(x, y): -- cgit v1.2.3 From 50f93a94d4337b5a4f268d0832bf0fea55f55c37 Mon Sep 17 00:00:00 2001 From: qzhangjhu Date: Wed, 28 Feb 2018 10:08:29 -0500 Subject: Corrections on Python3 page --- python3.html.markdown | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index b0f04a02..019934cb 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -790,11 +790,11 @@ class Superhero(Human): # This calls the parent class constructor: super().__init__(name) - # overload the sing method + # override the sing method def sing(self): return 'Dun, dun, DUN!' - # add an additional class method + # add an additional instance method def boast(self): for power in self.superpowers: print("I wield the power of {pow}!".format(pow=power)) @@ -817,7 +817,7 @@ if __name__ == '__main__': # Calls parent method but uses its own class attribute print(sup.get_species()) # => Superhuman - # Calls overloaded method + # Calls overridden method print(sup.sing()) # => Dun, dun, DUN! # Calls method from Human @@ -872,7 +872,7 @@ class Batman(Superhero, Bat): def __init__(self, *args, **kwargs): # Typically to inherit attributes you have to call super: - #super(Batman, self).__init__(*args, **kwargs) + # super(Batman, self).__init__(*args, **kwargs) # However we are dealing with multiple inheritance here, and super() # only works with the next base class in the MRO list. # So instead we explicitly call __init__ for all ancestors. @@ -901,7 +901,7 @@ if __name__ == '__main__': # Calls parent method but uses its own class attribute print(sup.get_species()) # => Superhuman - # Calls overloaded method + # Calls overridden method print(sup.sing()) # => nan nan nan nan nan batman! # Calls method from Human, because inheritance order matters -- cgit v1.2.3 From b6aed7a0b38bf189922dbc47ed802de3c9769b73 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E7=90=86=E7=B5=B5=E5=AD=90?= <41843094+lowlevelware@users.noreply.github.com> Date: Sun, 29 Jul 2018 11:53:33 +0900 Subject: added example for f-string Literal string interpolation is new in python 3.6 [pep-0498](https://www.python.org/dev/peps/pep-0498/) --- python3.html.markdown | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index 019934cb..d6cfbf59 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -138,6 +138,10 @@ len("This is a string") # => 16 # still use the old style of formatting: "%s can be %s the %s way" % ("Strings", "interpolated", "old") # => "Strings can be interpolated the old way" +# You can also format using f-strings or formatted string literals +name = "Reiko" +f"She said her name is {name}." # => "She said her name is Reiko" + # None is an object None # => None -- cgit v1.2.3 From 04de3a348ab825f3b34eb38d07dcb3cdfc6feb7a Mon Sep 17 00:00:00 2001 From: Roberto Fernandez Diaz Date: Tue, 7 Aug 2018 11:01:04 +0200 Subject: Clarification about sets I indicate that a set doesn't contain duplicate elements and add a little example --- python3.html.markdown | 3 +++ 1 file changed, 3 insertions(+) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index d6cfbf59..b378a8c6 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -7,6 +7,7 @@ contributors: - ["Zachary Ferguson", "http://github.com/zfergus2"] - ["evuez", "http://github.com/evuez"] - ["Rommel Martinez", "https://ebzzry.io"] + - ["Roberto Fernandez Diaz", "https://github.com/robertofd1995"] filename: learnpython3.py --- @@ -352,6 +353,8 @@ valid_set = {(1,), 1} # Add one more item to the set filled_set = some_set filled_set.add(5) # filled_set is now {1, 2, 3, 4, 5} +# Sets do not have duplicate elements +filled_set.add(5) # it remains as before {1, 2, 3, 4, 5} # Do set intersection with & other_set = {3, 4, 5, 6} -- cgit v1.2.3 From 56258dfb72c17192d1963d56da6aaf12624b3e43 Mon Sep 17 00:00:00 2001 From: Joseph G Date: Thu, 11 Oct 2018 14:10:16 -0700 Subject: Add f-string clarification. --- python3.html.markdown | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index b378a8c6..7683bc60 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -139,9 +139,11 @@ len("This is a string") # => 16 # still use the old style of formatting: "%s can be %s the %s way" % ("Strings", "interpolated", "old") # => "Strings can be interpolated the old way" -# You can also format using f-strings or formatted string literals +# You can also format using f-strings or formatted string literals (in Python 3.6+) name = "Reiko" f"She said her name is {name}." # => "She said her name is Reiko" +# You can basically put any Python statement inside the braces and it will be output in the string. +f"{name} is {len(name)} characters long." # None is an object -- cgit v1.2.3 From 30cdf4b25327e01c751db384e42692fd95178db1 Mon Sep 17 00:00:00 2001 From: Divay Prakash Date: Fri, 26 Oct 2018 02:35:15 +0530 Subject: Fix tuple unpacking example in python3, closes #3130 (#3328) --- python3.html.markdown | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'python3.html.markdown') diff --git a/python3.html.markdown b/python3.html.markdown index 7683bc60..c7fbf342 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -281,7 +281,8 @@ a, b, c = (1, 2, 3) # a is now 1, b is now 2 and c is now 3 # You can also do extended unpacking a, *b, c = (1, 2, 3, 4) # a is now 1, b is now [2, 3] and c is now 4 # Tuples are created by default if you leave out the parentheses -d, e, f = 4, 5, 6 +d, e, f = 4, 5, 6 # tuple 4, 5, 6 is unpacked into variables d, e and f +# respectively such that d = 4, e = 5 and f = 6 # Now look how easy it is to swap two values e, d = d, e # d is now 5 and e is now 4 -- cgit v1.2.3