From ed4fbb6aa4b60a67b6756b71a3849bf42200522e Mon Sep 17 00:00:00 2001 From: evuez Date: Tue, 13 Oct 2015 16:53:48 +0200 Subject: [PATCH] Add property to Classes This adds the property decorator (getter, setter, deleter) to the class example. Also update scopes functions to fit PEP8. --- python3.html.markdown | 41 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 36 insertions(+), 5 deletions(-) diff --git a/python3.html.markdown b/python3.html.markdown index 617a4fb6..38758078 100644 --- a/python3.html.markdown +++ b/python3.html.markdown @@ -463,7 +463,7 @@ with open("myfile.txt") as f: filled_dict = {"one": 1, "two": 2, "three": 3} our_iterable = filled_dict.keys() -print(our_iterable) # => range(1,10). This is an object that implements our Iterable interface +print(our_iterable) # => dict_keys(['one', 'two', 'three']). This is an object that implements our Iterable interface. # We can loop over it. for i in our_iterable: @@ -552,19 +552,19 @@ x, y = swap(x, y) # => x = 2, y = 1 # Function Scope x = 5 -def setX(num): +def set_x(num): # Local var x not the same as global variable x x = num # => 43 print (x) # => 43 -def setGlobalX(num): +def set_global_x(num): global x print (x) # => 5 x = num # global var x is now set to 6 print (x) # => 6 -setX(43) -setGlobalX(6) +set_x(43) +set_global_x(6) # Python has first class functions @@ -613,6 +613,9 @@ class Human: # Assign the argument to the instance's name attribute self.name = name + # Initialize property + self.age = 0 + # An instance method. All methods take "self" as the first argument def say(self, msg): return "{name}: {message}".format(name=self.name, message=msg) @@ -628,6 +631,23 @@ class Human: def grunt(): return "*grunt*" + # A property is just like a getter. + # It turns the method age() into an read-only attribute + # of the same name. + @property + def age(self): + return self._age + + # This allows the property to be set + @age.setter + def age(self, age): + self._age = age + + # This allows the property to be deleted + @age.deleter + def age(self): + del self._age + # Instantiate a class i = Human(name="Ian") @@ -647,6 +667,17 @@ j.get_species() # => "H. neanderthalensis" # Call the static method Human.grunt() # => "*grunt*" +# Update the property +i.age = 42 + +# Get the property +i.age # => 42 + +# Delete the property +del i.age +i.age # => raises an AttributeError + + #################################################### ## 6. Modules