diff -r 8249ae9d570a -r 88a01948450d getting-started-with-functions/script.rst --- a/getting-started-with-functions/script.rst Wed Nov 17 23:24:23 2010 +0530 +++ b/getting-started-with-functions/script.rst Wed Nov 17 23:24:57 2010 +0530 @@ -23,7 +23,8 @@ .. Author : Anoop Jacob Thomas Internal Reviewer : External Reviewer : - Checklist OK? : [2010-10-05] + Language Reviewer : Bhanukiran + Checklist OK? : [2010-10-05] ============================== @@ -32,29 +33,29 @@ {{{ 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 -function return value. +define functions, arguments to functions, docstrings, and function +return value. {{{ switch to next slide, Function }}} -While writing code, we would like to reduce the number of lines of -code and using functions is a way of reusing the code. A function is -a portion of code within a larger program that performs a specific -task and is relatively independent of the remaining code. Now let us -get more familiar with functions, +While writing code, we always want to reduce the number of lines of +code and functions is a way of reusing the code. Thus the same lines +of code can be used as many times as needed. A function is a portion of code +within a larger program that performs a specific task and is +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 -variable and with different values of x the value of function will -change. When x is one f(1) will return the value 1 and f(2) will -return us the value 4. Let us now see how to define the function f(x) -in Python. +Consider a mathematical function f(x) = x square. Here x is a variable +and with different values of x the value of function will change. When +x is one f(1) will return the value 1 and f(2) will return us the +value 4. Let us now see how to define the function f(x) in python. {{{ switch to next slide, define f(x) in Python }}} @@ -64,22 +65,19 @@ 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. - -Now, let us see what we did. The first line ``def f(x)`` is used to -define the name and the parameters to the function. ``def`` is a -keyword and ``f`` is the name of the function and ``x`` the parameter -of the 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. +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 +name and the parameters to the function and the second line is used to +fix what the function is supposed to return. ``def`` is a keyword and +``f`` is the name of the function and ``x`` the parameter of the +function. {{{ switch to next slide, problem statement 1 }}} @@ -96,18 +94,18 @@ 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() @@ -127,22 +125,22 @@ {{{ 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 ``avg`` and add doc-string to it. Do the following, +function does, and that is called a docstring. Let us modify the +function ``avg`` and add docstring to it. Do the following, :: def avg(a,b): @@ -150,7 +148,7 @@ 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. @@ -170,7 +168,7 @@ 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 }}} @@ -238,8 +236,8 @@ {{{ switch to next slide, even_digits }}} .. def even_digits( n ): -.. """returns True if all the digits of number n is even -.. returns False if all the digits of number n is not even""" +.. """returns True if all the digits in the number n are 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: @@ -290,9 +288,6 @@ 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!