--- a/getting-started-with-lists/script.rst Mon Nov 08 02:12:28 2010 +0530
+++ b/getting-started-with-lists/script.rst Thu Nov 11 02:28:55 2010 +0530
@@ -19,18 +19,20 @@
.. #. getting started with lists
.. #. basic datatypes
-.. Author : Puneeth
- Internal Reviewer : Amit
+.. Author : Amit
+ Internal Reviewer : Anoop Jacob Thomas <anoop@fossee.in>
External Reviewer :
Checklist OK? : <put date stamp here, if OK> [2010-10-05]
+.. #[[Anoop: Slides contain only outline and summary
+
Script
------
+ {{{ Show the slide containing title }}}
+
Hello friends and welcome to the tutorial on getting started with
lists.
- {{{ Show the slide containing title }}}
-
{{{ Show the slide containing the outline slide }}}
In this tutorial we will be getting acquainted with a python data
@@ -40,11 +42,15 @@
* Structure of lists
* Access list elements
* Append elements to lists
- * Deleting elements from lists
+ * Delete elements from lists
List is a compound data type, it can contain data of other data
types. List is also a sequence data type, all the elements are in
-order and there order has a meaning.
+order and the order has a meaning.
+
+.. #[[Anoop: "all the elements are in order and **there** order has a
+ meaning." - I guess something is wrong here, I am not able to
+ follow this.]]
We will first create an empty list with no elements. On your IPython
shell type ::
@@ -55,43 +61,58 @@
This is an empty list without any elements.
-* Filled lists
+.. #[[Anoop: the document has to be continous, without any
+ subheadings, removing * Filled lists]]
-Lets now define a list, nonempty and fill it with some random elements.
+Lets now see how to define a non-empty list. We do it as,::
-nonempty = ['spam', 'eggs', 100, 1.234]
+ nonempty = ['spam', 'eggs', 100, 1.234]
Thus the simplest way of creating a list is typing out a sequence
of comma-separated values (items) between square brackets.
-All the list items need not have the same data type.
-
-
+All the list items need not be of the same data type.
As we can see lists can contain different kinds of data. In the
-previous example 'spam' and 'eggs' are strings and 100 and 1.234
+previous example 'spam' and 'eggs' are strings and 100 and 1.234 are
integer and float. Thus we can put elements of heterogenous types in
-lists. Thus list themselves can be one of the element types possible
-in lists. Thus lists can also contain other lists. Example ::
+lists including list itself.
+
+.. #[[Anoop: the sentence "Thus list themselves can be one of the
+ element types possible in lists" is not clear, rephrase it.]]
- list_in_list=[[4,2,3,4],'and', 1, 2, 3, 4]
+Example ::
+
+ listinlist=[[4,2,3,4],'and', 1, 2, 3, 4]
-We access list elements using the number of index. The
-index begins from 0. So for list nonempty, nonempty[0] gives the
-first element, nonempty[1] the second element and so on and
-nonempty[3] the last element. ::
+We access list elements using the index. The index begins from 0. So
+for list nonempty, nonempty[0] gives the first element, nonempty[1]
+the second element and so on and nonempty[3] the last element. ::
nonempty[0]
nonempty[1]
nonempty[3]
-We can also access the elememts from the end using negative indices ::
+Following is an exercise that you must do.
+
+%% %% What happens when you do nonempty[-1].
+
+Please, pause the video here. Do the exercise and then continue.
+
+.. #[[Anoop: was negative indices introduced earlier, if not may be we
+ can ask them to try out nonempty[-1] and see what happens and then
+ tell that it gives the last element in the list.]]
+
+As you can see you get the last element which is 1.234.
+
+
+In python negative indices are used to access elements from the end::
nonempty[-1]
nonempty[-2]
nonempty[-4]
--1 gives the last element which is the 4th element , -2 second to last and -4 gives the fourth
-from last element which is first element.
+-1 gives the last element which is the 4th element , -2 second to last
+and -4 gives the fourth from last element which is first element.
We can append elements to the end of a list using append command. ::
@@ -100,12 +121,23 @@
nonempty.append(6)
nonempty
-As we can see non empty appends 'onemore' and 6 at the end.
+Following are exercises that you must do.
+
+%% %% What is the syntax to get the element 'and'
+in the list,listinlist ?
+%% %% How would you get 'and' using negative indices?
+
+Please, pause the video here. Do the exercise and then continue.
+
+The solution is on your screen
+
+
+As we can see non empty appends 'onemore' and 6 at the end.
Using len function we can check the number of elements in the list
-nonempty. In this case it being 6 ::
+nonempty. In this case it 6 ::
len(nonempty)
@@ -121,23 +153,50 @@
deletes the element at index 1, i.e the second element of the
list, 'eggs'. The other way is removing element by content. Lets say
one wishes to delete 100 from nonempty list the syntax of the command
-should be ::
-
- nonempty.remove(100)
+should be
-but what if their were two 100's. To check that lets do a small
+.. #[[Anoop: let x = [1,2,1,3]
+ now x.remove(x[2])
+ still x is [2,1,3] so that is not the way to remove
+ element by index, it removed first occurrence of 1(by
+ content) and not based on index, so make necessary
+ changes]]
+
+::
+
+ nonempty.remove(100)
+
+but what if there were two 100's. To check that lets do a small
experiment. ::
- nonempty.append('python')
+ nonempty.append('spam')
nonempty
- nonempty.remove('python')
+ nonempty.remove('spam')
nonempty
-If we check a now we will see that the first occurence 'spam' is removed
+If we check now we will see that the first occurence 'spam' is removed
thus remove removes the first occurence of the element in the sequence
and leaves others untouched.
+
+
+
+.. #[[Anoop: does it have two spams or two pythons?]]
+
+.. #[[Anoop: there are no exercises/solved problems in this script,
+ add them]]
+
+Following are exercises that you must do.
+
+%% %% Remove the third element from the list, listinlist.
+
+%% %% Remove 'and' from the list, listinlist.
+
+Please, pause the video here. Do the exercise and then continue.
+
+
+
{{{Slide for Summary }}}
@@ -151,7 +210,7 @@
-{{{ Sponsored by Fossee Slide }}}
+{{{ show Sponsored by Fossee Slide }}}
This tutorial was created as a part of FOSSEE project.
@@ -159,7 +218,7 @@
Thank You
-
+..
* Author : Amit Sethi
* First Reviewer :
* Second Reviewer : Nishanth