Merge pull request #581 from ggarza/python_pep8

[python/en] Modify python to be pep8 compliant

python.html.markdown

@@ -16,7 +16,9 @@ Note: This article applies to Python 2.7 specifically, but should be applicable
 to Python 2.x. Look for another tour of Python 3 soon!
 
 ```python
+
 # Single line comments start with a hash.
+
 """ Multiline strings can be written
     using three "'s, and are often used
     as comments
@@ -27,60 +29,60 @@ to Python 2.x. Look for another tour of Python 3 soon!
 ####################################################
 
 # You have numbers
-3 #=> 3
+3  # => 3
 
 # Math is what you would expect
-1 + 1 #=> 2
+1 + 1  # => 2
-8 - 1 #=> 7
+8 - 1  # => 7
-10 * 2 #=> 20
+10 * 2  # => 20
-35 / 5 #=> 7
+35 / 5  # => 7
 
 # Division is a bit tricky. It is integer division and floors the results
 # automatically.
-5 / 2 #=> 2
+5 / 2  # => 2
 
 # To fix division we need to learn about floats.
 2.0     # This is a float
-11.0 / 4.0 #=> 2.75 ahhh...much better
+11.0 / 4.0  # => 2.75 ahhh...much better
 
 # Enforce precedence with parentheses
-(1 + 3) * 2 #=> 8
+(1 + 3) * 2  # => 8
 
 # Boolean values are primitives
 True
 False
 
 # negate with not
-not True #=> False
+not True  # => False
-not False #=> True
+not False  # => True
 
 # Equality is ==
-1 == 1 #=> True
+1 == 1  # => True
-2 == 1 #=> False
+2 == 1  # => False
 
 # Inequality is !=
-1 != 1 #=> False
+1 != 1  # => False
-2 != 1 #=> True
+2 != 1  # => True
 
 # More comparisons
-1 < 10 #=> True
+1 < 10  # => True
-1 > 10 #=> False
+1 > 10  # => False
-2 <= 2 #=> True
+2 <= 2  # => True
-2 >= 2 #=> True
+2 >= 2  # => True
 
 # Comparisons can be chained!
-1 < 2 < 3 #=> True
+1 < 2 < 3  # => True
-2 < 3 < 2 #=> False
+2 < 3 < 2  # => False
 
 # Strings are created with " or '
 "This is a string."
 'This is also a string.'
 
 # Strings can be added too!
-"Hello " + "world!" #=> "Hello world!"
+"Hello " + "world!"  # => "Hello world!"
 
 # A string can be treated like a list of characters
-"This is a string"[0] #=> 'T'
+"This is a string"[0]  # => 'T'
 
 # % can be used to format strings, like this:
 "%s can be %s" % ("strings", "interpolated")
@@ -92,12 +94,12 @@ not False #=> True
 "{name} wants to eat {food}".format(name="Bob", food="lasagna")
 
 # None is an object
-None #=> None
+None  # => None
 
 # Don't use the equality "==" symbol to compare objects to None
 # Use "is" instead
-"etc" is None #=> False
+"etc" is None  # => False
-None is None  #=> True
+None is None  # => True
 
 # The 'is' operator tests for object identity. This isn't
 # very useful when dealing with primitive values, but is
@@ -105,8 +107,8 @@ None is None  #=> True
 
 # None, 0, and empty strings/lists all evaluate to False.
 # All other values are True
-bool(0)  #=> False
+bool(0)  # => False
-bool("") #=> False
+bool("")  # => False
 
 
 ####################################################
@@ -121,14 +123,14 @@ print "I'm also Python!"
 
 # No need to declare variables before assigning to them.
 some_var = 5    # Convention is to use lower_case_with_underscores
-some_var #=> 5
+some_var  # => 5
 
 # Accessing a previously unassigned variable is an exception.
 # See Control Flow to learn more about exception handling.
 some_other_var  # Raises a name error
 
 # if can be used as an expression
-"yahoo!" if 3 > 2 else 2 #=> "yahoo!"
+"yahoo!" if 3 > 2 else 2  # => "yahoo!"
 
 # Lists store sequences
 li = []
@@ -136,63 +138,63 @@ li = []
 other_li = [4, 5, 6]
 
 # Add stuff to the end of a list with append
-li.append(1)    #li is now [1]
+li.append(1)    # li is now [1]
-li.append(2)    #li is now [1, 2]
+li.append(2)    # li is now [1, 2]
-li.append(4)    #li is now [1, 2, 4]
+li.append(4)    # li is now [1, 2, 4]
-li.append(3)    #li is now [1, 2, 4, 3]
+li.append(3)    # li is now [1, 2, 4, 3]
 # Remove from the end with pop
-li.pop()        #=> 3 and li is now [1, 2, 4]
+li.pop()        # => 3 and li is now [1, 2, 4]
 # Let's put it back
 li.append(3)    # li is now [1, 2, 4, 3] again.
 
 # Access a list like you would any array
-li[0] #=> 1
+li[0]  # => 1
 # Look at the last element
-li[-1] #=> 3
+li[-1]  # => 3
 
 # Looking out of bounds is an IndexError
-li[4] # Raises an IndexError
+li[4]  # Raises an IndexError
 
 # You can look at ranges with slice syntax.
 # (It's a closed/open range for you mathy types.)
-li[1:3] #=> [2, 4]
+li[1:3]  # => [2, 4]
 # Omit the beginning
-li[2:] #=> [4, 3]
+li[2:]  # => [4, 3]
 # Omit the end
-li[:3] #=> [1, 2, 4]
+li[:3]  # => [1, 2, 4]
 # Select every second entry
-li[::2] #=>[1,4]
+li[::2]   # =>[1, 4]
 # Revert the list
-li[::-1] #=> [3, 4, 2, 1]
+li[::-1]   # => [3, 4, 2, 1]
 # Use any combination of these to make advanced slices
 # li[start:end:step]
 
 # Remove arbitrary elements from a list with "del"
-del li[2] # li is now [1, 2, 3]
+del li[2]   # li is now [1, 2, 3]
 
 # You can add lists
-li + other_li #=> [1, 2, 3, 4, 5, 6] - Note: li and other_li is left alone
+li + other_li   # => [1, 2, 3, 4, 5, 6] - Note: li and other_li is left alone
 
 # Concatenate lists with "extend()"
-li.extend(other_li) # Now li is [1, 2, 3, 4, 5, 6]
+li.extend(other_li)   # Now li is [1, 2, 3, 4, 5, 6]
 
 # Check for existence in a list with "in"
-1 in li #=> True
+1 in li   # => True
 
 # Examine the length with "len()"
-len(li) #=> 6
+len(li)   # => 6
 
 
 # Tuples are like lists but are immutable.
 tup = (1, 2, 3)
-tup[0] #=> 1
+tup[0]   # => 1
 tup[0] = 3  # Raises a TypeError
 
 # You can do all those list thingies on tuples too
-len(tup) #=> 3
+len(tup)   # => 3
-tup + (4, 5, 6) #=> (1, 2, 3, 4, 5, 6)
+tup + (4, 5, 6)   # => (1, 2, 3, 4, 5, 6)
-tup[:2] #=> (1, 2)
+tup[:2]   # => (1, 2)
-2 in tup #=> True
+2 in tup   # => True
 
 # You can unpack tuples (or lists) into variables
 a, b, c = (1, 2, 3)     # a is now 1, b is now 2 and c is now 3
@@ -208,60 +210,60 @@ empty_dict = {}
 filled_dict = {"one": 1, "two": 2, "three": 3}
 
 # Look up values with []
-filled_dict["one"] #=> 1
+filled_dict["one"]   # => 1
 
 # Get all keys as a list with "keys()"
-filled_dict.keys() #=> ["three", "two", "one"]
+filled_dict.keys()   # => ["three", "two", "one"]
 # Note - Dictionary key ordering is not guaranteed.
 # Your results might not match this exactly.
 
 # Get all values as a list with "values()"
-filled_dict.values() #=> [3, 2, 1]
+filled_dict.values()   # => [3, 2, 1]
 # Note - Same as above regarding key ordering.
 
 # Check for existence of keys in a dictionary with "in"
-"one" in filled_dict #=> True
+"one" in filled_dict   # => True
-1 in filled_dict #=> False
+1 in filled_dict   # => False
 
 # Looking up a non-existing key is a KeyError
-filled_dict["four"] # KeyError
+filled_dict["four"]   # KeyError
 
 # Use "get()" method to avoid the KeyError
-filled_dict.get("one") #=> 1
+filled_dict.get("one")   # => 1
-filled_dict.get("four") #=> None
+filled_dict.get("four")   # => None
 # The get method supports a default argument when the value is missing
-filled_dict.get("one", 4) #=> 1
+filled_dict.get("one", 4)   # => 1
-filled_dict.get("four", 4) #=> 4
+filled_dict.get("four", 4)   # => 4
 
 # "setdefault()" inserts into a dictionary only if the given key isn't present
-filled_dict.setdefault("five", 5) #filled_dict["five"] is set to 5
+filled_dict.setdefault("five", 5)  # filled_dict["five"] is set to 5
-filled_dict.setdefault("five", 6) #filled_dict["five"] is still 5
+filled_dict.setdefault("five", 6)  # filled_dict["five"] is still 5
 
 
 # Sets store ... well sets
 empty_set = set()
 # Initialize a "set()" with a bunch of values
-some_set = set([1,2,2,3,4]) # some_set is now set([1, 2, 3, 4])
+some_set = set([1, 2, 2, 3, 4])   # some_set is now set([1, 2, 3, 4])
 
 # Since Python 2.7, {} can be used to declare a set
-filled_set = {1, 2, 2, 3, 4} # => {1, 2, 3, 4}
+filled_set = {1, 2, 2, 3, 4}   # => {1, 2, 3, 4}
 
 # Add more items to a set
-filled_set.add(5) # filled_set is now {1, 2, 3, 4, 5}
+filled_set.add(5)   # filled_set is now {1, 2, 3, 4, 5}
 
 # Do set intersection with &
 other_set = {3, 4, 5, 6}
-filled_set & other_set #=> {3, 4, 5}
+filled_set & other_set   # => {3, 4, 5}
 
 # Do set union with |
-filled_set | other_set #=> {1, 2, 3, 4, 5, 6}
+filled_set | other_set   # => {1, 2, 3, 4, 5, 6}
 
 # Do set difference with -
-{1,2,3,4} - {2,3,5} #=> {1, 4}
+{1, 2, 3, 4} - {2, 3, 5}   # => {1, 4}
 
 # Check for existence in a set with in
-2 in filled_set #=> True
+2 in filled_set   # => True
-10 in filled_set #=> False
+10 in filled_set   # => False
 
 
 ####################################################
@@ -337,17 +339,18 @@ def add(x, y):
     return x + y    # Return values with a return statement
 
 # Calling functions with parameters
-add(5, 6) #=> prints out "x is 5 and y is 6" and returns 11
+add(5, 6)   # => prints out "x is 5 and y is 6" and returns 11
 
 # Another way to call functions is with keyword arguments
 add(y=6, x=5)   # Keyword arguments can arrive in any order.
 
+
 # You can define functions that take a variable number of
 # positional arguments
 def varargs(*args):
     return args
 
-varargs(1, 2, 3) #=> (1,2,3)
+varargs(1, 2, 3)   # => (1, 2, 3)
 
 
 # You can define functions that take a variable number of
@@ -356,7 +359,8 @@ def keyword_args(**kwargs):
     return kwargs
 
 # Let's call it to see what happens
-keyword_args(big="foot", loch="ness") #=> {"big": "foot", "loch": "ness"}
+keyword_args(big="foot", loch="ness")   # => {"big": "foot", "loch": "ness"}
+
 
 # You can do both at once, if you like
 def all_the_args(*args, **kwargs):
@@ -372,9 +376,10 @@ 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(*args)   # equivalent to foo(1, 2, 3, 4)
-all_the_args(**kwargs) # equivalent to foo(a=3, b=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, **kwargs)   # equivalent to foo(1, 2, 3, 4, a=3, b=4)
+
 
 # Python has first class functions
 def create_adder(x):
@@ -383,23 +388,24 @@ def create_adder(x):
     return adder
 
 add_10 = create_adder(10)
-add_10(3) #=> 13
+add_10(3)   # => 13
 
 # There are also anonymous functions
-(lambda x: x > 2)(3) #=> True
+(lambda x: x > 2)(3)   # => True
 
 # There are built-in higher order functions
-map(add_10, [1,2,3]) #=> [11, 12, 13]
+map(add_10, [1, 2, 3])   # => [11, 12, 13]
-filter(lambda x: x > 5, [3, 4, 5, 6, 7]) #=> [6, 7]
+filter(lambda x: x > 5, [3, 4, 5, 6, 7])   # => [6, 7]
 
 # We can use list comprehensions for nice maps and filters
-[add_10(i) for i in [1, 2, 3]]  #=> [11, 12, 13]
+[add_10(i) for i in [1, 2, 3]]  # => [11, 12, 13]
-[x for x in [3, 4, 5, 6, 7] if x > 5] #=> [6, 7]
+[x for x in [3, 4, 5, 6, 7] if x > 5]   # => [6, 7]
 
 ####################################################
 ## 5. Classes
 ####################################################
 
+
 # We subclass from object to get a class.
 class Human(object):
 
@@ -413,7 +419,7 @@ class Human(object):
 
     # An instance method. All methods take "self" as the first argument
     def say(self, msg):
-       return "%s: %s" % (self.name, msg)
+        return "%s: %s" % (self.name, msg)
 
     # A class method is shared among all instances
     # They are called with the calling class as the first argument
@@ -432,18 +438,18 @@ i = Human(name="Ian")
 print(i.say("hi"))     # prints out "Ian: hi"
 
 j = Human("Joel")
-print(j.say("hello"))  #prints out "Joel: hello"
+print(j.say("hello"))  # prints out "Joel: hello"
 
 # Call our class method
-i.get_species() #=> "H. sapiens"
+i.get_species()   # => "H. sapiens"
 
 # Change the shared attribute
 Human.species = "H. neanderthalensis"
-i.get_species() #=> "H. neanderthalensis"
+i.get_species()   # => "H. neanderthalensis"
-j.get_species() #=> "H. neanderthalensis"
+j.get_species()   # => "H. neanderthalensis"
 
 # Call the static method
-Human.grunt() #=> "*grunt*"
+Human.grunt()   # => "*grunt*"
 
 
 ####################################################
@@ -452,12 +458,12 @@ Human.grunt() #=> "*grunt*"
 
 # You can import modules
 import math
-print(math.sqrt(16) )#=> 4
+print(math.sqrt(16))  # => 4
 
 # You can get specific functions from a module
 from math import ceil, floor
-print(ceil(3.7))  #=> 4.0
+print(ceil(3.7))  # => 4.0
-print(floor(3.7)) #=> 3.0
+print(floor(3.7))   # => 3.0
 
 # You can import all functions from a module.
 # Warning: this is not recommended
@@ -465,7 +471,7 @@ from math import *
 
 # You can shorten module names
 import math as m
-math.sqrt(16) == m.sqrt(16) #=> True
+math.sqrt(16) == m.sqrt(16)   # => True
 
 # Python modules are just ordinary python files. You
 # can write your own, and import them. The name of the
@@ -486,10 +492,12 @@ def double_numbers(iterable):
     for i in iterable:
         yield i + i
 
-# generator creates the value on the fly
+# A generator creates values on the fly.
-# instead of generating and returning all values at once it creates one in each iteration
+# Instead of generating and returning all values at once it creates one in each
-# this means values bigger than 15 wont be processed in double_numbers
+# iteration.  This means values bigger than 15 wont be processed in
-# note range is a generator too, creating a list 1-900000000 would take lot of time to be made
+# double_numbers.
+# Note range is a generator too. Creating a list 1-900000000 would take lot of
+# time to be made
 _range = range(1, 900000000)
 # will double all numbers until a result >=30 found
 for i in double_numbers(_range):
@@ -500,7 +508,8 @@ for i in double_numbers(_range):
 
 # Decorators
 # in this example beg wraps say
-# Beg will call say. If say_please is True then it will change the returned message
+# Beg will call say. If say_please is True then it will change the returned
+# message
 from functools import wraps
 
 
@@ -523,8 +532,6 @@ def say(say_please=False):
 
 print(say())  # Can you buy me a beer?
 print(say(say_please=True))  # Can you buy me a beer? Please! I am poor :(
-
-
 ```
 
 ## Ready For More?