Merge remote-tracking branch 'adambard/master' into adambard/master-cn

1 files changed, 301 insertions, 136 deletions

diff --git a/python.html.markdown b/python.html.markdown
index e7ee6fbd..5572e38e 100644
--- a/python.html.markdown
+++ b/python.html.markdown
@@ -2,22 +2,26 @@
 language: python
 contributors:
     - ["Louie Dinh", "http://ldinh.ca"]
+    - ["Amin Bandali", "http://aminbandali.com"]
+    - ["Andre Polykanine", "https://github.com/Oire"]
 filename: learnpython.py
 ---
 
-Python was created by Guido Van Rossum in the early 90's. It is now one of the most popular
-languages in existence. I fell in love with Python for its syntactic clarity. Its basically
+Python was created by Guido Van Rossum in the early 90s. It is now one of the most popular
+languages in existence. I fell in love with Python for its syntactic clarity. It's basically
 executable pseudocode.
 
 Feedback would be highly appreciated! You can reach me at [@louiedinh](http://twitter.com/louiedinh) or louiedinh [at] [google's email service]
 
 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!
+to Python 2.x. For Python 3.x, take a look at the [Python 3 tutorial](http://learnxinyminutes.com/docs/python3/).
 
 ```python
-# Single line comments start with a hash.
+
+# Single line comments start with a number symbol.
+
 """ Multiline strings can be written
-    using three "'s, and are often used
+    using three "s, and are often used
     as comments
 """
 
@@ -26,60 +30,85 @@ 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
-8 - 1 #=> 7
-10 * 2 #=> 20
-35 / 5 #=> 7
+1 + 1  # => 2
+8 - 1  # => 7
+10 * 2  # => 20
+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
+
+# Result of integer division truncated down both for positive and negative.
+5 // 3     # => 1
+5.0 // 3.0 # => 1.0 # works on floats too
+-5 // 3  # => -2
+-5.0 // 3.0 # => -2.0
+
+# Modulo operation
+7 % 3 # => 1
+
+# Exponentiation (x to the yth power)
+2**4 # => 16
 
 # Enforce precedence with parentheses
-(1 + 3) * 2 #=> 8
+(1 + 3) * 2  # => 8
 
-# Boolean values are primitives
-True
-False
+# Boolean Operators
+# Note "and" and "or" are case-sensitive
+True and False #=> False
+False or True #=> True
+
+# Note using Bool operators with ints
+0 and 2 #=> 0
+-5 or 0 #=> -5
+0 == False #=> True
+2 == True #=> False
+1 == True #=> True
 
 # negate with not
-not True #=> False
-not False #=> True
+not True  # => False
+not False  # => True
 
 # Equality is ==
-1 == 1 #=> True
-2 == 1 #=> False
+1 == 1  # => True
+2 == 1  # => False
 
 # Inequality is !=
-1 != 1 #=> False
-2 != 1 #=> True
+1 != 1  # => False
+2 != 1  # => True
 
 # More comparisons
-1 < 10 #=> True
-1 > 10 #=> False
-2 <= 2 #=> True
-2 >= 2 #=> True
+1 < 10  # => True
+1 > 10  # => False
+2 <= 2  # => True
+2 >= 2  # => True
 
-# Comparisons can be chained  !
-1 < 2 < 3 #=> True
-2 < 3 < 2 #=> False
+# Comparisons can be chained!
+1 < 2 < 3  # => True
+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!"
+# Strings can be added without using '+'
+"Hello " "world!"  # => "Hello world!"
+
+# ... or multiplied
+"Hello" * 3  # => "HelloHelloHello"
 
 # 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")
@@ -91,12 +120,12 @@ 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
-None is None  #=> True
+# Don't use the equality "==" symbol to compare objects to None
+# Use "is" instead
+"etc" is None  # => False
+None is None  # => True
 
 # The 'is' operator tests for object identity. This isn't
 # very useful when dealing with primitive values, but is
@@ -104,28 +133,27 @@ None is None  #=> True
 
 # None, 0, and empty strings/lists all evaluate to False.
 # All other values are True
-0 == False  #=> True
-"" == False #=> True
+bool(0)  # => False
+bool("")  # => False
 
 
 ####################################################
 ## 2. Variables and Collections
 ####################################################
 
-# Printing is pretty easy
+# Python has a print statement
 print "I'm Python. Nice to meet you!"
 
-
 # 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 = []
@@ -133,57 +161,68 @@ 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(2)    #li is now [1, 2]
-li.append(4)    #li is now [1, 2, 4]
-li.append(3)    #li is now [1, 2, 4, 3]
+li.append(1)    # li is now [1]
+li.append(2)    # li is now [1, 2]
+li.append(4)    # li is now [1, 2, 4]
+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
+# Assign new values to indexes that have already been initialized with =
+li[0] = 42
+li[0]  # => 42
+li[0] = 1  # Note: setting it back to the original value
 # 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]
+# Reverse a copy of the list
+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]
+# Remove arbitrary elements from a list with "del"
+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: values for li and for other_li are not modified.
 
-# Concatenate lists with extend
-li.extend(other_li) # Now li is [1, 2, 3, 4, 5, 6]
+# Concatenate lists with "extend()"
+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
+# Check for existence in a list with "in"
+1 in li   # => True
 
-# Examine the length with len
-len(li) #=> 6
+# Examine the length with "len()"
+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
-tup + (4, 5, 6) #=> (1, 2, 3, 4, 5, 6)
-tup[:2] #=> (1, 2)
-2 in tup #=> True
+len(tup)   # => 3
+tup + (4, 5, 6)   # => (1, 2, 3, 4, 5, 6)
+tup[:2]   # => (1, 2)
+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
@@ -199,60 +238,68 @@ 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
-filled_dict.keys() #=> ["three", "two", "one"]
+# Get all keys as a list with "keys()"
+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
-filled_dict.values() #=> [3, 2, 1]
+# Get all values as a list with "values()"
+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
-1 in filled_dict #=> False
+# Check for existence of keys in a dictionary with "in"
+"one" in filled_dict   # => True
+1 in filled_dict   # => False
 
- # Looking up a non-existing key is a KeyError
-filled_dict["four"] # KeyError
+# Looking up a non-existing key is a KeyError
+filled_dict["four"]   # KeyError
 
-# Use get method to avoid the KeyError
-filled_dict.get("one") #=> 1
-filled_dict.get("four") #=> None
+# Use "get()" method to avoid the KeyError
+filled_dict.get("one")   # => 1
+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("four", 4) #=> 4
+filled_dict.get("one", 4)   # => 1
+filled_dict.get("four", 4)   # => 4
+# note that filled_dict.get("four") is still => None
+# (get doesn't set the value in the dictionary)
+
+# set the value of a key with a syntax similar to lists
+filled_dict["four"] = 4  # now, filled_dict["four"] => 4
 
-# Setdefault method is a safe way to add new key-value pair into dictionary
-filled_dict.setdefault("five", 5) #filled_dict["five"] is set to 5
-filled_dict.setdefault("five", 6) #filled_dict["five"] is still 5
+# "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", 6)  # filled_dict["five"] is still 5
 
 
-# Sets store ... well sets
+# Sets store ... well sets (which are like lists but can contain no duplicates)
 empty_set = set()
-# Initialize a set with a bunch of values
-some_set = set([1,2,2,3,4]) # filled_set is now set([1, 2, 3, 4])
+# 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])
+
+# order is not guaranteed, even though it may sometimes look sorted
+another_set = set([4, 3, 2, 2, 1])  # another_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
-10 in filled_set #=> False
+2 in filled_set   # => True
+10 in filled_set   # => False
 
 
 ####################################################
@@ -263,7 +310,7 @@ filled_set | other_set #=> {1, 2, 3, 4, 5, 6}
 some_var = 5
 
 # Here is an if statement. Indentation is significant in python!
-# prints "some var is smaller than 10"
+# prints "some_var is smaller than 10"
 if some_var > 10:
     print "some_var is totally bigger than 10."
 elif some_var < 10:    # This elif clause is optional.
@@ -280,11 +327,11 @@ prints:
     mouse is a mammal
 """
 for animal in ["dog", "cat", "mouse"]:
-    # You can use % to interpolate formatted strings
-    print "%s is a mammal" % animal
-    
+    # You can use {0} to interpolate formatted strings. (See above.)
+    print "{0} is a mammal".format(animal)
+
 """
-`range(number)` returns a list of numbers 
+"range(number)" returns a list of numbers
 from zero to the given number
 prints:
     0
@@ -296,6 +343,18 @@ for i in range(4):
     print i
 
 """
+"range(lower, upper)" returns a list of numbers
+from the lower number to the upper number
+prints:
+    4
+    5
+    6
+    7
+"""
+for i in range(4, 8):
+    print i
+
+"""
 While loops go until a condition is no longer met.
 prints:
     0
@@ -312,42 +371,54 @@ while x < 4:
 
 # Works on Python 2.6 and up:
 try:
-    # Use raise to raise an error
+    # Use "raise" to raise an error
     raise IndexError("This is an index error")
 except IndexError as e:
     pass    # Pass is just a no-op. Usually you would do recovery here.
-
+except (TypeError, NameError):
+    pass    # Multiple exceptions can be handled together, if required.
+else:   # Optional clause to the try/except block. Must follow all except blocks
+    print "All good!"   # Runs only if the code in try raises no exceptions
+finally: #  Execute under all circumstances
+    print "We can clean up resources here"
+
+# Instead of try/finally to cleanup resources you can use a with statement
+with open("myfile.txt") as f:
+    for line in f:
+        print line
 
 ####################################################
 ## 4. Functions
 ####################################################
 
-# Use def to create new functions
+# Use "def" to create new functions
 def add(x, y):
-    print "x is %s and y is %s" % (x, y)
+    print "x is {0} and y is {1}".format(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
+# positional args, which will be interpreted as a tuple if you do not use the *
 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
-# keyword arguments, as well
+# keyword args, as well, which will be interpreted as a dict if you do not use **
 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):
@@ -359,13 +430,37 @@ all_the_args(1, 2, a=3, b=4) prints:
     {"a": 3, "b": 4}
 """
 
-# When calling functions, you can do the opposite of varargs/kwargs!
-# Use * to expand tuples and use ** to expand kwargs.
+# When calling functions, you can do the opposite of args/kwargs!
+# Use * to expand positional args and use ** to expand keyword args.
 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 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)
+
+# you can pass args and kwargs along to other functions that take args/kwargs
+# by expanding them with * and ** respectively
+def pass_all_the_args(*args, **kwargs):
+    all_the_args(*args, **kwargs)
+    print varargs(*args)
+    print keyword_args(**kwargs)
+
+# Function Scope
+x = 5
+
+def setX(num):
+    # Local var x not the same as global variable x
+    x = num # => 43
+    print x # => 43
+
+def setGlobalX(num):
+    global x
+    print x # => 5
+    x = num # global var x is now set to 6
+    print x # => 6
+
+setX(43)
+setGlobalX(6)
 
 # Python has first class functions
 def create_adder(x):
@@ -374,18 +469,19 @@ 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]
-filter(lambda x: x > 5, [3, 4, 5, 6, 7]) #=> [6, 7]
+map(add_10, [1, 2, 3])   # => [11, 12, 13]
+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]
-[x for x in [3, 4, 5, 6, 7] if x > 5] #=> [6, 7]
+[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]
+
 
 ####################################################
 ## 5. Classes
@@ -394,17 +490,20 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7]) #=> [6, 7]
 # We subclass from object to get a class.
 class Human(object):
 
-     # A class attribute. It is shared by all instances of this class
+    # A class attribute. It is shared by all instances of this class
     species = "H. sapiens"
 
-    # Basic initializer
+    # Basic initializer, this is called when this class is instantiated.
+    # Note that the double leading and trailing underscores denote objects
+    # or attributes that are used by python but that live in user-controlled
+    # namespaces. You should not invent such names on your own.
     def __init__(self, name):
         # Assign the argument to the instance's name attribute
         self.name = name
 
-    # An instance method. All methods take self as the first argument
+    # An instance method. All methods take "self" as the first argument
     def say(self, msg):
-       return "%s: %s" % (self.name, msg)
+        return "{0}: {1}".format(self.name, msg)
 
     # A class method is shared among all instances
     # They are called with the calling class as the first argument
@@ -423,18 +522,18 @@ 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"
-j.get_species() #=> "H. neanderthalensis"
+i.get_species()   # => "H. neanderthalensis"
+j.get_species()   # => "H. neanderthalensis"
 
 # Call the static method
-Human.grunt() #=> "*grunt*"
+Human.grunt()   # => "*grunt*"
 
 
 ####################################################
@@ -443,12 +542,12 @@ 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 floor(3.7) #=> 3.0
+print ceil(3.7)  # => 4.0
+print floor(3.7)   # => 3.0
 
 # You can import all functions from a module.
 # Warning: this is not recommended
@@ -456,10 +555,13 @@ 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
+# you can also test that the functions are equivalent
+from math import sqrt
+math.sqrt == m.sqrt == sqrt  # => True
 
 # Python modules are just ordinary python files. You
-# can write your own, and import them. The name of the 
+# can write your own, and import them. The name of the
 # module is the same as the name of the file.
 
 # You can find out which functions and attributes
@@ -468,14 +570,77 @@ import math
 dir(math)
 
 
+####################################################
+## 7. Advanced
+####################################################
+
+# Generators help you make lazy code
+def double_numbers(iterable):
+    for i in iterable:
+        yield i + i
+
+# A generator creates values on the fly.
+# Instead of generating and returning all values at once it creates one in each
+# iteration.  This means values bigger than 15 wont be processed in
+# double_numbers.
+# Note xrange is a generator that does the same thing range does.
+# Creating a list 1-900000000 would take lot of time and space to be made.
+# xrange creates an xrange generator object instead of creating the entire list
+# like range does.
+# We use a trailing underscore in variable names when we want to use a name that
+# would normally collide with a python keyword
+xrange_ = xrange(1, 900000000)
+
+# will double all numbers until a result >=30 found
+for i in double_numbers(xrange_):
+    print i
+    if i >= 30:
+        break
+
+
+# Decorators
+# in this example beg wraps say
+# Beg will call say. If say_please is True then it will change the returned
+# message
+from functools import wraps
+
+
+def beg(target_function):
+    @wraps(target_function)
+    def wrapper(*args, **kwargs):
+        msg, say_please = target_function(*args, **kwargs)
+        if say_please:
+            return "{} {}".format(msg, "Please! I am poor :(")
+        return msg
+
+    return wrapper
+
+
+@beg
+def say(say_please=False):
+    msg = "Can you buy me a beer?"
+    return msg, say_please
+
+
+print say()  # Can you buy me a beer?
+print say(say_please=True)  # Can you buy me a beer? Please! I am poor :(
 ```
 
-## Further Reading
+## Ready For More?
 
-Still up for more? Try:
+### Free Online
 
+* [Automate the Boring Stuff with Python](https://automatetheboringstuff.com)
 * [Learn Python The Hard Way](http://learnpythonthehardway.org/book/)
 * [Dive Into Python](http://www.diveintopython.net/)
 * [The Official Docs](http://docs.python.org/2.6/)
 * [Hitchhiker's Guide to Python](http://docs.python-guide.org/en/latest/)
 * [Python Module of the Week](http://pymotw.com/2/)
+* [A Crash Course in Python for Scientists](http://nbviewer.ipython.org/5920182)
+* [First Steps With Python](https://realpython.com/learn/python-first-steps/)
+
+### Dead Tree
+
+* [Programming Python](http://www.amazon.com/gp/product/0596158106/ref=as_li_qf_sp_asin_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596158106&linkCode=as2&tag=homebits04-20)
+* [Dive Into Python](http://www.amazon.com/gp/product/1441413022/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1441413022&linkCode=as2&tag=homebits04-20)
+* [Python Essential Reference](http://www.amazon.com/gp/product/0672329786/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0672329786&linkCode=as2&tag=homebits04-20)