From 6684e4613836b2d4ac04daf24e993a0fbd55a799 Mon Sep 17 00:00:00 2001
From: Kushal Das <kushaldas@gmail.com>
Date: Sat, 9 May 2015 11:41:13 +0530
Subject: [PATCH] Merging changes from py3 branch.

---
 docs/datastructure.rst         | 28 ++++++++---------
 docs/file.rst                  | 30 +++++++++---------
 docs/functions.rst             | 46 ++++++++++++++--------------
 docs/ifelse.rst                | 24 +++++++--------
 docs/index.rst                 |  3 +-
 docs/installation.rst          | 12 +++++---
 docs/looping.rst               | 52 +++++++++++++++----------------
 docs/operatorsexpressions.rst  | 24 +++++++--------
 docs/projectstructure.rst      |  4 +--
 docs/strings.rst               |  8 ++---
 docs/variablesanddatatypes.rst | 56 ++++++++++++++--------------------
 11 files changed, 139 insertions(+), 148 deletions(-)

diff --git a/docs/datastructure.rst b/docs/datastructure.rst
index d4eb243..bfaa8e7 100644
--- a/docs/datastructure.rst
+++ b/docs/datastructure.rst
@@ -170,7 +170,7 @@ Tuples are data separated by comma.
     >>> a[1]
     'Debian'
     >>> for x in a:
-    ...     print x,
+    ...     print(x, end=' ')
     ...
     Fedora Debian Kubuntu Pardus
 
@@ -316,7 +316,7 @@ If you want to loop through a dict use *iteritems()* method.
     >>> data
     {'Kushal': 'Fedora', 'Jace': 'Mac', 'kart_': 'Debian', 'parthan': 'Ubuntu'}
     >>> for x, y in data.iteritems():
-    ...     print "%s uses %s" % (x, y)
+    ...     print("%s uses %s" % (x, y))
     ...
     Kushal uses Fedora
     Jace uses Mac
@@ -355,7 +355,7 @@ If you want to loop through a list (or any sequence) and get iteration number at
 ::
 
     >>> for i, j in enumerate(['a', 'b', 'c']):
-    ...     print i, j
+    ...     print(i, j)
     ...
     0 a
     1 b
@@ -368,7 +368,7 @@ You may also need to iterate through two sequences same time, for that use *zip(
     >>> a = ['Pradeepto', 'Kushal']
     >>> b = ['OpenSUSE', 'Fedora']
     >>> for x, y in zip(a, b):
-    ...     print "%s uses %s" % (x, y)
+    ...     print("%s uses %s" % (x, y))
     ...
     Pradeepto uses OpenSUSE
     Kushal uses Fedora
@@ -392,11 +392,11 @@ In this example , you have to take number of students as input , then ask marks
         data[name] = marks
     for x, y in data.iteritems():
         total =  sum(y)
-        print "%s 's  total marks %d" % (x, total)
+        print("%s 's  total marks %d" % (x, total))
         if total < 120:
-            print "%s failed :(" % x
+            print("%s failed :(" % x)
         else:
-            print "%s passed :)" % x
+            print("%s passed :)" % x)
 
 The output
 
@@ -426,24 +426,24 @@ In this example we will multiply two matrices. First we will take input the numb
 
     #!/usr/bin/env python
     n = int(raw_input("Enter the value of n: "))
-    print "Enter values for the Matrix A"
+    print("Enter values for the Matrix A")
     a = []
     for i in range(0, n):
         a.append([int(x) for x in raw_input("").split(" ")])
-    print "Enter values for the Matrix B"
+    print("Enter values for the Matrix B")
     b = []
     for i in range(0, n):
         b.append([int(x) for x in raw_input("").split(" ")])
     c = []
     for i in range(0, n):
         c.append([a[i][j] * b[j][i] for j in range(0,n)])
-    print "After matrix multiplication"
-    print "-" * 10 * n
+    print("After matrix multiplication")
+    print("-" * 10 * n)
     for x in c:
         for y in x:
-            print "%5d" % y,
-        print ""
-    print "-" * 10 * n
+            print("%5d" % y, end=' ')
+        print("")
+    print("-" * 10 * n)
 
 The output
 
diff --git a/docs/file.rst b/docs/file.rst
index b56cb40..1567d5d 100644
--- a/docs/file.rst
+++ b/docs/file.rst
@@ -79,8 +79,8 @@ You can even loop through the lines in a file object.
 ::
 
     >>> fobj = open("sample.txt")
-    >>> for x in fobj:
-    ...     print(x, end='')
+    >>> for x in f:
+    ...     print(x, end=' ')
     ...
     I love Python
     Pradeepto loves KDE
@@ -90,10 +90,10 @@ Let us write a program which will take the file name as the input from the user
 
 ::
 
-    #!/usr/bin/env python
-    name = raw_input("Enter the file name: ")
+    #!/usr/bin/env python3
+    name = input("Enter the file name: ")
     fobj = open(name)
-    print fobj.read()
+    print(fobj.read())
     fobj.close()
 
 In the last line you can see that we closed the file object with the help of close() method.
@@ -141,11 +141,11 @@ In this example we will copy a given text file to another file.
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     import sys
     if len(sys.argv) < 3:
-        print "Wrong parameter"
-        print "./copyfile.py file1 file2"
+        print("Wrong parameter")
+        print("./copyfile.py file1 file2")
         sys.exit(1)
     f1 = open(sys.argv[1])
     s = f1.read()
@@ -162,12 +162,12 @@ The first value in *sys.argv* is the name of the command itself.
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     import sys
-    print "First value", sys.argv[0]
-    print "All values"
+    print("First value", sys.argv[0])
+    print("All values")
     for i, x  in enumerate(sys.argv):
-        print i, x
+        print(i, x)
 
 The output
 
@@ -224,7 +224,7 @@ Let us try to write an application which will count the spaces, tabs, and lines
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
 
     import os
     import sys
@@ -261,7 +261,7 @@ Let us try to write an application which will count the spaces, tabs, and lines
         """
         if os.path.exists(path):
             spaces, tabs, lines = parse_file(path)
-            print "Spaces %d. tabs %d. lines %d" % (spaces, tabs, lines)
+            print("Spaces %d. tabs %d. lines %d" % (spaces, tabs, lines))
             return True
         else:
             return False
@@ -318,4 +318,4 @@ line by line and find out the number of CPU(s).
 
 .. tip:: Always remember to read files line by line than reading them as a whole. Sometimes you may have to read files which are way bigger than your available RAM. 
 
-After you do this, try to write your own lscpu command in Python :)
+After you do this, try to write your own lscpu command in Python :)
\ No newline at end of file
diff --git a/docs/functions.rst b/docs/functions.rst
index 9a0e83e..9162546 100644
--- a/docs/functions.rst
+++ b/docs/functions.rst
@@ -35,15 +35,15 @@ Remember the palindrome program we wrote in the last chapter. Let us write a fun
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     def palindrome(s):
         return s == s[::-1]
     if __name__ == '__main__':
-        s = raw_input("Enter a string: ")
+        s = input("Enter a string: ")
         if palindrome(s):
-            print "Yay a palindrome"
+            print("Yay a palindrome")
         else:
-            print "Oh no, not a palindrome"
+            print("Oh no, not a palindrome")
 
 Now run the code :)
 
@@ -54,15 +54,15 @@ To understand local and global variables we will go through two examples.
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     def change(b):
         a = 90
-        print a
+        print(a)
     a = 9
-    print "Before the function call ", a
-    print "inside change function",
+    print("Before the function call ", a)
+    print("inside change function", end=' ')
     change(a)
-    print "After the function call ", a
+    print("After the function call ", a)
 
 The output
 ::
@@ -76,16 +76,16 @@ First we are assigning *9* to *a*, then calling change function, inside of that
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     def change(b):
         global a
         a = 90
-        print a
+        print(a)
     a = 9
-    print "Before the function call ", a
-    print "inside change function",
+    print("Before the function call ", a)
+    print("inside change function", end=' ')
     change(a)
-    print "After the function call ", a
+    print("After the function call ", a)
 
 Here by using global keyword we are telling that *a* is globally defined, so when we are changing a's value inside the function it is actually changing for the *a* outside of the function also.
 
@@ -137,8 +137,8 @@ To avoid this you can write more idiomatic Python, like the following
     >>> def f(a, data=None):
     ...     if data is None:
     ...         data = []
-    ...         data.append(a)
-    ...         return data
+    ...     data.append(a)
+    ...     return data
     ...
     >>> print f(1)
     [1]
@@ -152,7 +152,7 @@ Keyword arguments
 ::
 
     >>> def func(a, b=5, c=10):
-    ...     print 'a is', a, 'and b is', b, 'and c is', c
+    ...     print('a is', a, 'and b is', b, 'and c is', c)
     ...
     >>> func(12, 24)
     a is 12 and b is 24 and c is 10
@@ -166,7 +166,7 @@ In the above example you can see we are calling the function with variable names
 ::
 
     >>> def func(a, b=13, v):
-    ...     print a, b, v
+    ...     print(a, b, v)
     ...
     File "<stdin>", line 1
     SyntaxError: non-default argument follows default argument
@@ -201,7 +201,7 @@ In Python we use docstrings to explain how to use the code, it will be useful in
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     import math
 
     def longest_side(a, b):
@@ -216,7 +216,7 @@ In Python we use docstrings to explain how to use the code, it will be useful in
         return math.sqrt(a*a + b*b)
 
     if __name__ == '__main__':
-        print longest_side(4, 5)
+        print(longest_side(4, 5))
 
 We will learn more on docstrings in reStructuredText chapter.
 
@@ -237,9 +237,9 @@ In Python any function can act as higher order function.
     ...     return func(value)
     ...
     >>> lst = high(dir, int)
-    >>> print lst[-3:]
+    >>> print(lst[-3:])
     ['imag', 'numerator', 'real']
-    >>> print lst
+    >>> print(lst)
 
 .. note:: To know more read `this link <http://docs.python.org/2/faq/programming.html#how-do-you-make-a-higher-order-function-in-python>`_.
 
@@ -256,6 +256,6 @@ Example::
     ...     "Returns the square of a given number."
     ...     return num * num
     ... 
-    >>> print map(square, lst)
+    >>> print(map(square, lst))
     [1, 4, 9, 16, 25]
 
diff --git a/docs/ifelse.rst b/docs/ifelse.rst
index c5cdff3..c0fba46 100644
--- a/docs/ifelse.rst
+++ b/docs/ifelse.rst
@@ -20,10 +20,10 @@ If the value of *expression* is true (anything other than zero), do the what is
 
 ::
 
-    #!/usr/bin/env python
-    number = int(raw_input("Enter a number: "))
+    #!/usr/bin/env python3
+    number = int(input("Enter a number: "))
     if number < 100:
-        print "The number is less than 100"
+        print("The number is less than 100")
 
 Then we run it
 
@@ -40,12 +40,12 @@ Now in the above example we want to print "Greater than" if the number is greate
 
 ::
 
-    #!/usr/bin/env python
-    number = int(raw_input("Enter a number: "))
+    #!/usr/bin/env python3
+    number = int(input("Enter a number: "))
     if number < 100:
-        print "The number is less than 100"
+        print("The number is less than 100")
     else:
-        print "The number is greater than 100"
+        print("The number is greater than 100")
 
 The output
 
@@ -59,16 +59,16 @@ Another very basic example
 
 ::
 
-    >>> x = int(raw_input("Please enter an integer: "))
+    >>> x = int(input("Please enter an integer: "))
     >>> if x < 0:
     ...      x = 0
-    ...      print 'Negative changed to zero'
+    ...      print('Negative changed to zero')
     ... elif x == 0:
-    ...      print 'Zero'
+    ...      print('Zero')
     ... elif x == 1:
-    ...      print 'Single'
+    ...      print('Single')
     ... else:
-    ...      print 'More'
+    ...      print('More')
 
 Truth value testing
 ===================
diff --git a/docs/index.rst b/docs/index.rst
index 4fdbd0d..db0fdfc 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -8,8 +8,7 @@ Welcome to Python for you and me
 
 This is a simple book to learn Python programming language, it is for the programmers who are new to Python.
 
-
-The Python 2.x version of the same book can be found `here <http://pymbook.readthedocs.org/en/py2/>`_.
+The Python 2.x version of the same book can be found `here <http://pymbook.readthedocs.org/en/latest/>`_.
 
 Contents:
 
diff --git a/docs/installation.rst b/docs/installation.rst
index 3b8215f..5e610ca 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -4,28 +4,30 @@
 Installation
 ============
 
-In this chapter you will learn how to install Python
+In this chapter you will learn how to install Python3, the latest of the language.
+
 
 On Windows
 ==========
 
-You have to download the latest Windows(TM) installer from the Python site http://www.python.org/ftp/python/2.7.3/python-2.7.3.msi . Install it just as any other Windows software.
+You have to download the latest Windows(TM) installer from the Python site, `x86_64 <https://www.python.org/ftp/python/3.4.1/python-3.4.1.amd64.msi>`_ and
+`i686 <https://www.python.org/ftp/python/3.4.1/python-3.4.1.msi>`_. Install it just as any other Windows software.
 
 On GNU/Linux
 ============
 
-Generally all GNU/Linux distributions come with Python, so no need to worry about that :) If you don't have it then you can install it by either downloading from the Python website or from your distribution's repository.
+You will have to install the latest Python from the distribution's repository.
 
 For Fedora
 
 ::
 
-    [user@host]$ sudo yum install python
+    [user@host]$ sudo yum install python3
 
 For Debian
 
 ::
 
-    [user@host]$ sudo apt-get install python
+    [user@host]$ sudo apt-get install python3
 
 
diff --git a/docs/looping.rst b/docs/looping.rst
index 820232f..86284c3 100644
--- a/docs/looping.rst
+++ b/docs/looping.rst
@@ -23,7 +23,7 @@ The code we want to reuse must be indented properly under the while statement. T
 
     >>> n = 0
     >>> while n < 11:
-    ...     print n
+    ...     print(n)
     ...     n += 1
     ...
     0
@@ -47,10 +47,10 @@ Let us try to solve *Fibonacci* series. In this series we get the next number by
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     a, b = 0, 1
     while b < 100:
-        print b
+        print(b)
         a, b = b, a + b
 
 The output
@@ -72,14 +72,14 @@ The output
 
 In the first line of the code we are initializing *a* and *b*, then looping while b's value is less than 100. Inside the loop first we are printing the value of *b* and then in the next line putting the value of *b* to *a* and *a + b* to *b* in the same line.
 
-If you put a trailing comma in the *print* statement , then it will print in the same line
+In your print function call if you pass another argument called end and pass a space string, it will print in the same line with space delimiter. The default value for end is '\n'.
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     a, b = 0, 1
     while b < 100:
-        print b,
+        print(b,)
         a, b = b, a + b
 
 The output
@@ -96,7 +96,7 @@ Let us write a program to evaluate the power series. The series looks like e**x
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     x = float(raw_input("Enter the value of x: "))
     n = term = num = 1
     sum = 1.0
@@ -106,7 +106,7 @@ Let us write a program to evaluate the power series. The series looks like e**x
         n += 1
         if term < 0.0001:
             break
-    print "No of Times= %d and Sum= %f" % (n, sum)
+    print("No of Times= %d and Sum= %f" % (n, sum))
 
 The output
 ::
@@ -139,7 +139,7 @@ In this example we are going to print the multiplication table up to 10.
 
     #!/usr/bin/env python3
     i = 1
-    print("-" * 50),
+    print("-" * 50)
     while i < 11:
         n = 1
         while n <= 10:
@@ -181,7 +181,7 @@ In a *print* statement if we multiply the string with an integer *n* , the strin
     >>> print("#" * 20)
     ####################
     >>> print("--" * 20)
-    ---------------------------------------
+    ----------------------------------------
     >>> print("-" * 40)
     ----------------------------------------
 
@@ -194,7 +194,7 @@ Design 1
 ::
 
     #!/usr/bin/env python3
-    row = int(raw_input("Enter the number of rows: "))
+    row = int(input("Enter the number of rows: "))
     n = row
     while n >= 0:
         x =  "*" * n
@@ -215,8 +215,8 @@ The output
 Design 2
 ::
 
-    #!/usr/bin/env python
-    n = int(raw_input("Enter the number of rows: "))
+    #!/usr/bin/env python3
+    n = int(input("Enter the number of rows: "))
     i = 1
     while i <= n:
         print("*" * i)
@@ -237,7 +237,7 @@ Design 3
 ::
 
     #!/usr/bin/env python
-    row = int(raw_input("Enter the number of rows: "))
+    row = int(input("Enter the number of rows: "))
     n = row
     while n >= 0:
         x = "*" * n
@@ -258,7 +258,7 @@ The output
 
 Lists
 =====
-List datastructure
+
 
 We are going to learn a data structure called list before we go ahead to learn more on looping. Lists can be written as a list of comma-separated values (items) between square brackets.
 
@@ -329,7 +329,7 @@ There is another to loop by using *for* statement. In Python the *for* statement
 
     >>> a = ['Fedora', 'is', 'powerfull']
     >>> for x in a:
-    ...     print(x, end=" ")
+    ...     print x,
     ...
     Fedora is powerfull
 
@@ -340,7 +340,6 @@ We can also do things like
     >>> a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
     >>> for x in a[::2]:
     ...     print(x)
-    ...
     1
     3
     5
@@ -350,17 +349,18 @@ We can also do things like
 range() function
 ================
 
-range() is a buitin function. From the help document
+range() is a buitin class. From the help document
 
 ::
 
-    range(...)
-    range([start,] stop[, step]) -> list of integers
-    Return a list containing an arithmetic progression of integers.
-    range(i, j) returns [i, i+1, i+2, ..., j-1]; start (!) defaults to 0.
-    When step is given, it specifies the increment (or decrement).
-    For example, range(4) returns [0, 1, 2, 3].  The end point is omitted!
-    These are exactly the valid indices for a list of 4 elements.
+class range(object)
+ |  range(stop) -> range object
+ |  range(start, stop[, step]) -> range object
+ |  
+ |  Return a virtual sequence of numbers from start to stop by step.
+ |  
+ |  Methods defined here:
+
 
 Now if you want to see this help message on your system type *help(range)* in the Python interpreter. *help(s)* will return help message on the object *s*. Examples of *range* function
 
@@ -446,7 +446,7 @@ This is a very simple game of sticks. There are 21 sticks, first the user picks
         if sticks_taken >= 5 or sticks_taken <= 0:
             print("Wrong choice")
             continue
-        print("Computer took: " , (5 - sticks_taken) , "n\n")
+        print("Computer took: " , (5 - sticks_taken) , "\n")
         sticks -= 5
 
 
diff --git a/docs/operatorsexpressions.rst b/docs/operatorsexpressions.rst
index 621d687..4629c95 100644
--- a/docs/operatorsexpressions.rst
+++ b/docs/operatorsexpressions.rst
@@ -34,11 +34,11 @@ The code
 
 ::
 
-    #!/usr/bin/env python
-    days = int(raw_input("Enter days: "))
+    #!/usr/bin/env python3
+    days = int(nput("Enter days: "))
     months = days / 30
     days = days % 30
-    print "Months = %d Days = %d" % (months, days)
+    print("Months = %d Days = %d" % (months, days))
 
 The output
 
@@ -52,9 +52,9 @@ In the first line I am taking the input of days, then getting the months and day
 
 ::
 
-    #!/usr/bin/env python
-    days = int(raw_input("Enter days: "))
-    print "Months = %d Days = %d" % (divmod(days, 30))
+    #!/usr/bin/env python3
+    days = int(input("Enter days: "))
+    print("Months = %d Days = %d" % (divmod(days, 30)))
 
 The divmod(num1, num2) function returns two values , first is the division of num1 and num2 and in second the modulo of num1 and num2.
 
@@ -142,11 +142,11 @@ shorthand.py example
 
 .. code-block:: python
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     N = 100
     a = 2
     while a < N:
-        print "%d" % a
+        print("%d" % a)
         a *= a
 
 The output
@@ -255,14 +255,14 @@ This is a program to evaluate the quadratic equation
 
 ::
 
-    #!/usr/bin/env python3
+    #!/usr/bin/env python
     import math
     a = int(input("Enter value of a: "))
     b = int(input("Enter value of b: "))
     c = int(input("Enter value of c: "))
     d = b * b - 4 * a * c
     if d < 0:
-        print("ROOTS are imaginary")
+        print "ROOTS are imaginary"
     else:
         root1 = (-b + math.sqrt(d)) / (2.0 * a)
         root2 = (-b - math.sqrt(d)) / (2.0 * a)
@@ -276,7 +276,7 @@ In this example we are going to calculate the salary of a camera salesman. His b
 
 ::
 
-    #!/usr/bin/env python3
+    #!/usr/bin/env python
     basic_salary = 1500
     bonus_rate = 200
     commision_rate = 0.02
@@ -286,7 +286,7 @@ In this example we are going to calculate the salary of a camera salesman. His b
     commision = (commision_rate * numberofcamera * price)
     print("Bonus        = %6.2f" % bonus)
     print("Commision    = %6.2f" % commision)
-    print("Gross salary = %6.2f" % (basic_salary + bonus + commision))
+    print("Gross salary = %6.2f") % (basic_salary + bonus + commision)
 
 The output
 
diff --git a/docs/projectstructure.rst b/docs/projectstructure.rst
index 048886a..b43cfcf 100644
--- a/docs/projectstructure.rst
+++ b/docs/projectstructure.rst
@@ -173,8 +173,8 @@ Creating account
 First register yourself in `this link <https://testpypi.python.org/pypi?%3Aaction=register_form>`_. You will
 receive an email with a link, go to that link and confirm your registration.
 
-.pypirc file
--------------
+ .pypirc file
+ -------------
 
  Your account details genrally stay inside a file called *.pypirc* under your home directory.
  The content of the file will look like
diff --git a/docs/strings.rst b/docs/strings.rst
index a9cd1d5..e50d8b1 100644
--- a/docs/strings.rst
+++ b/docs/strings.rst
@@ -173,9 +173,9 @@ Palindrome are the kind of strings which are same from left or right whichever w
     s = raw_input("Please enter a string: ")
     z = s[::-1]
     if s == z:
-        print "The string is a palindrome"
+        print("The string is a palindrome")
     else:
-        print "The string is not a palindrome"
+        print("The string is not a palindrome")
 
 The output
 
@@ -196,8 +196,8 @@ In this example we will count the number of words in a given line
 ::
 
     #!/usr/bin/env python
-    s = raw_input("Enter a line: ")
-    print "The number of words in the line are %d" % (len(s.split(" ")))
+    s = input("Enter a line: ")
+    print("The number of words in the line are %d" % (len(s.split(" "))))
 
 The output
 ::
diff --git a/docs/variablesanddatatypes.rst b/docs/variablesanddatatypes.rst
index b906239..e7b72ea 100644
--- a/docs/variablesanddatatypes.rst
+++ b/docs/variablesanddatatypes.rst
@@ -9,27 +9,17 @@ Every programming language is having own grammar rules just like the other langu
 Keywords and Identifiers
 ========================
 
-Python codes can be divided into identifiers. Identifiers (also referred to as names) are described by the following lexical definitions:
+The following identifiers are used as reserved words, or keywords of the language, and cannot be used as ordinary identifiers. They must be spelled exactly as written here:
 
 ::
 
-    identifier ::= (letter|"_") (letter | digit | "_")*
-    letter ::= lowercase | uppercase
-    lowercase ::= "a"..."z"
-    uppercase ::= "A"..."Z"
-    digit ::= "0"..."9"
-
-This means *_abcd* is a valid identifier where as *1sd* is not. The following identifiers are used as reserved words, or keywords of the language, and cannot be used as ordinary identifiers. They must be spelled exactly as written here:
-
-::
-
-    and       del      from      not   while
-    as        elif     global    or    with
-    assert    else     if        pass  yield
-    break     except   import    print
-    class     exec     in        raise
-    continue  finally  is        return
-    def       for      lambda    try
+    False      class      finally    is         return
+    None       continue   for        lambda     try
+    True       def        from       nonlocal   while
+    and        del        global     not        with
+    as         elif       if         or         yield
+    assert     else       import     pass
+    break      except     in         raise
 
 In Python we don't specify what kind of data we are going to put in a variable. So you can directly write abc = 1 and abc will become an integer datatype. If you write abc = 1.0 abc will become of floating type. Here is a small program to add two given numbers
 
@@ -54,16 +44,16 @@ From the above example you can understand that to declare a variable in Python ,
 Reading input from the Keyboard
 ===============================
 
-Generally the real life Python codes do not need to read input from the keyboard. In Python we use raw_input function to do input. *raw_input("String to show")* , this will return a string as output. Let us write a program to read a number from the keyboard and check if it is less than 100 or not. Name of the program is testhundred.py
+Generally the real life Python codes do not need to read input from the keyboard. In Python we use input function to do input. *input("String to show")* , this will return a string as output. Let us write a program to read a number from the keyboard and check if it is less than 100 or not. Name of the program is testhundred.py
 
 .. code-block:: python
 
-    #!/usr/bin/env python
-    number = int(raw_input("Enter an integer: "))
+    #!/usr/bin/env python3
+    number = int(input("Enter an integer: "))
     if number < 100:
-        print "Your number is smaller than 100"
+        print("Your number is smaller than 100")
     else:
-        print "Your number is greater than 100"
+        print("Your number is greater than 100")
 
 The output
 
@@ -81,14 +71,14 @@ In the next program we are going to calculate investments.
 ::
 
     #!/usr/bin/env python
-    amount = float(raw_input("Enter amount: "))
-    inrate = float(raw_input("Enter Interest rate: "))
-    period = int(raw_input("Enter period: "))
+    amount = float(input("Enter amount: "))
+    inrate = float(input("Enter Interest rate: "))
+    period = int(input("Enter period: "))
     value = 0
     year = 1
     while year <= period:
         value = amount + (inrate * amount)
-        print "Year %d Rs. %.2f" % (year, value)
+        print("Year %d Rs. %.2f" % (year, value))
         amount = value
         year = year + 1
 
@@ -123,12 +113,12 @@ In the next program we will do an average of N numbers.
     sum = 0
     count = 0
     while count < N:
-        number = float(raw_input(""))
+        number = float(input(""))
         sum = sum + number
         count = count + 1
     average = float(sum)/N
-    print "N = %d , Sum = %f" % (N, sum)
-    print "Average = %f" % average
+    print("N = %d , Sum = %f" % (N, sum))
+    print("Average = %f") % average
 
 
 The output
@@ -156,12 +146,12 @@ In this program we will convert the given temperature to Celsius from Fahrenheit
 
 ::
 
-    #!/usr/bin/env python
+    #!/usr/bin/env python3
     fahrenheit = 0.0
-    print "Fahrenheit Celsius"
+    print("Fahrenheit Celsius")
     while fahrenheit <= 250:
         celsius = ( fahrenheit - 32.0 ) / 1.8 # Here we calculate the Celsius value
-        print "%5.1f %7.2f" % (fahrenheit , celsius)
+        print("%5.1f %7.2f" % (fahrenheit , celsius))
         fahrenheit = fahrenheit + 25
 
 The output