st-scripts: comparison getting-started-with-functions/script.rst

equal deleted inserted replaced

-:8249ae9d570a
+:88a01948450d
 .. Author              : Anoop Jacob Thomas <anoop@fossee.in>
 Internal Reviewer   :
 External Reviewer   :
-Checklist OK?       : <put date stamp here, if OK> [2010-10-05]
+Language Reviewer   : Bhanukiran
+Checklist OK?       : <put date stamp here, not OK> [2010-10-05]
 ==============================
 Getting started with functions
 ==============================
 {{{ show welcome slide }}}
-Hello and welcome to the tutorial, getting started with functions.
+Hello and welcome to the tutorial getting started with functions.
 {{{ switch to next slide, outline slide }}}
 In this tutorial we will learn about functions in python, how to
-define functions, passing arguments to functions, docstrings, and
+define functions, arguments to functions, docstrings, and function
-function return value.
+return value.
 {{{ switch to next slide, Function }}}
-While writing code, we would like to reduce the number of lines of
+While writing code, we always want to reduce the number of lines of
-code and using functions is a way of reusing the code.  A function is
+code and functions is a way of reusing the code. Thus the same lines
-a portion of code within a larger program that performs a specific
+of code can be used as many times as needed. A function is a portion of code
-task and is relatively independent of the remaining code. Now let us
+within a larger program that performs a specific task and is
-get more familiar with functions,
+relatively independent of the remaining code. Now let us get more
+familiar with functions,
 {{{ switch to next slide, f(x) a mathematical function }}}
-Consider a mathematical function f(x) = x squared. Here x is a
+Consider a mathematical function f(x) = x square. Here x is a variable
-variable and with different values of x the value of function will
+and with different values of x the value of function will change. When
-change. When x is one f(1) will return the value 1 and f(2) will
+x is one f(1) will return the value 1 and f(2) will return us the
-return us the value 4. Let us now see how to define the function f(x)
+value 4. Let us now see how to define the function f(x) in python.
-in Python.
 {{{ switch to next slide, define f(x) in Python }}}
 In your Ipython interpreter type the following,
 ::
 def f(x):
 	return x*x
-Let us see, if the function ``f``, we defined, works as we expect.
+Well that defined the function, so before learning what we did let us
+see if it returns the expected values, try,
 ::
 f(1)
 f(2)
-Yes, it returned 1 and 2 respectively.
+Yes, it returned 1 and 4 respectively. And now let us see what we did.
+We wrote two lines: The first line ``def f(x)`` is used to define the
-Now, let us see what we did. The first line ``def f(x)`` is used to
+name and the parameters to the function and the second line is used to
-define the name and the parameters to the function. ``def`` is a
+fix what the function is supposed to return. ``def`` is a keyword and
-keyword and ``f`` is the name of the function and ``x`` the parameter
+``f`` is the name of the function and ``x`` the parameter of the
-of the function.
+function.
-The second line is the body of the function. Incidentally, this
-function has a single line definition. Note that the body of the
-function is indented, just like any other code block, in Python.
 {{{ switch to next slide, problem statement 1 }}}
 %% 1 %% Write a python function named cube which computes the cube of
 a given number n.
 ::
 def cube(n):
 	return n**3
-Now let us see how to write functions without arguments.
+And now let us see how to write functions without arguments.
 {{{ switch to next slide, greet function }}}
-Let us define a new function called ``greet`` which will print ``Hello
+let us define a new function called ``greet`` which will print ``Hello
 World``.
 ::
 def greet():
 	print "Hello World!"
-Now try calling the function,
+now try calling the function,
 ::
 greet()
 Well that is a function which takes no arguments. Also note that it is
 Pause here and try to solve the problem yourself.
 {{{ switch to next slide, solution 2 }}}
-The problem can be solved as shown,
+The problem can be solved as,
 ::
 def avg(a,b):
 	return (a + b)/2
 Thus if we want a function to accept more arguments, we just list them
-separated with a comma between the parenthesis after the function name
+separated with a comma between the parenthesis after the function's name
 in the ``def`` line.
 {{{ switch to next slide, docstring }}}
 It is always a good practice to document the code that we write, and
 for a function we define we should write an abstract of what the
-function does, and that is called a doc-string. Let us modify the
+function does, and that is called a docstring. Let us modify the
-function ``avg`` and add doc-string to it. Do the following,
+function ``avg`` and add docstring to it. Do the following,
 ::
 def avg(a,b):
 """ avg takes two numbers as input (a & b), and
 	returns the average of a and b"""
 	return (a+b)/2
-Note that doc-strings are entered in the immediate line after the
+Note that docstrings are entered in the immediate line after the
 function definition and put as a triple quoted string. And here as far
 as the code functionality is concerned, we didn't do anything. We just
 added an abstract of what the function does.
 Now try this in the ipython interpreter.
 f?
 It doesn't have a docstring associated with it. Also we cannot infer
 anything from the function name, and thus we are forced to read the
-code to understand anything about the function.
+code to understand about the function.
 {{{ switch to next slide, exercise 3 }}}
 %% 3 %% Add docstring to the function f.
 Pause here and try to figure out what the function ``what`` does.
 {{{ switch to next slide, even_digits }}}
 .. def even_digits( n ):
-..    """returns True if all the digits of number n is even
+..    """returns True if all the digits in the number n are even,
-..    returns False if all the digits of number n is not even"""
+..    returns False if all the digits in the number n are not even"""
 ..     if n < 0: n = -n
 ..     while n > 0:
 ..         if n % 2 == 1:
 ..             return False
 ..         n /= 10
 - Passing parameters to a function
 - Returning values from a function
 We also did few code reading exercises.
-{{{ Show the "sponsored by FOSSEE" slide }}}
+{{{ switch to next slide, Thank you }}}
-This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
-Hope you have enjoyed and found it useful.
 Thank you!

changeset 521	88a01948450d
parent 484	a1828587a617