--- a/basic-data-type/script.rst Wed Oct 27 14:09:40 2010 +0530
+++ b/basic-data-type/script.rst Wed Oct 27 15:13:17 2010 +0530
@@ -1,13 +1,15 @@
.. Objectives
.. ----------
-.. Learn about Python Data Structures and Operators.(Remembering)
-.. Use them to do basic operations.(Applying)
+.. At the end of this tutorial, you should know --
+
+.. 1. Learn about Python Data Structures and Operators.(Remembering)
+.. #.Use them to do basic operations.(Applying)
.. Prerequisites
.. -------------
-
+.. None
.. Author : Amit Sethi
Internal Reviewer :
@@ -259,7 +261,7 @@
type ::
- In[]: greeting_string="hello"
+ greeting_string="hello"
greeting_string is now a string variable with the value "hello"
@@ -268,9 +270,9 @@
Python strings can actually be defined in three different ways ::
- In[]: k='Single quote'
- In[]: l="Double quote contain's single quote"
- In[]: m='''"Contain's both"'''
+ k='Single quote'
+ l="Double quote contain's single quote"
+ m='''"Contain's both"'''
.. #[Puneeth: Contain's? That's not a word!]
@@ -286,7 +288,7 @@
To create a tuple we use normal brackets '(' unlike '[' for lists.::
- In[]: num_tuple = (1, 2, 3, 4, 5, 6, 7, 8)
+ num_tuple = (1, 2, 3, 4, 5, 6, 7, 8)
Because of their sequential property there are certain functions and
operations we can apply to all of them.
@@ -297,13 +299,13 @@
They can be accessed using index numbers ::
- In[]: num_list[2]
- In[]: num_list[-1]
- In[]: greeting_string[1]
- In[]: greeting_string[3]
- In[]: greeting_string[-2]
- In[]: num_tuple[2]
- In[]: num_tuple[-3]
+ num_list[2]
+ num_list[-1]
+ greeting_string[1]
+ greeting_string[3]
+ greeting_string[-2]
+ num_tuple[2]
+ num_tuple[-3]
Indexing starts from 0 from left to right and from -1 when accessing lists
@@ -314,37 +316,37 @@
Addition gives a new sequence containing both sequences ::
- In[]: num_list+var_list
- In[]: a_string="another string"
- In[]: greeting_string+a_string
- In[]: t2=(3,4,6,7)
- In[]: num_tuple+t2
+ num_list+var_list
+ a_string="another string"
+ greeting_string+a_string
+ t2=(3,4,6,7)
+ num_tuple+t2
len function gives the length ::
- In[]: len(num_list)
- In[]: len(greeting_string)
- In[]: len(num_tuple)
+ len(num_list)
+ len(greeting_string)
+ len(num_tuple)
Prints the length the variable.
We can check the containership of an element using the 'in' keyword ::
- In[]: 3 in num_list
- In[]: 'H' in greeting_string
- In[]: 2 in num_tuple
+ 3 in num_list
+ 'H' in greeting_string
+ 2 in num_tuple
We see that it gives True and False accordingly.
Find maximum using max function and minimum using min::
- In[]: max(num_tuple)
- In[]: min(greeting_string)
+ max(num_tuple)
+ min(greeting_string)
Get a sorted list and reversed list using sorted and reversed function ::
- In[]: sorted(num_list)
- In[]: reversed(greeting_string)
+ sorted(num_list)
+ reversed(greeting_string)
As a consequence of the order one we access a group of elements together.
This is called slicing and striding.
@@ -355,29 +357,29 @@
Given a list ::
- In[]:j=[1,2,3,4,5,6]
+ j=[1,2,3,4,5,6]
Lets say we want elements starting from 2 and ending in 5.
For this we can do ::
- In[]: j[1:4]
+ j[1:4]
The syntax for slicing is, sequence variable name square bracket first
element index, colon, second element index. The last element however is not
included in the resultant list::
- In[]: j[:4]
+ j[:4]
If first element is left blank default is from beginning and if last
element is left blank it means till the end.
::
- In[]: j[1:]
+ j[1:]
- In[]: j[:]
+ j[:]
This effectively is the whole list.
@@ -397,8 +399,8 @@
But there are many important features in lists that differ from strings and
tuples. Lets see this by example.::
- In[]: new_num_list[1]=9
- In[]: greeting_string[1]='k'
+ new_num_list[1]=9
+ greeting_string[1]='k'
{{{ slide to show the error }}}
@@ -409,7 +411,7 @@
Now lets try ::
- In[]: new_tuple[1]=5
+ new_tuple[1]=5
Its the same error. This is because strings and tuples share the property
of being immutable. We cannot change the value at a particular index just
@@ -473,11 +475,11 @@
join function does the opposite. Joins a list to make a string.::
- In[]:','.join['List','joined','on','commas']
+ ','.join['List','joined','on','commas']
Thus we get a list joined on commas. Similarly we can do spaces.::
- In[]:' '.join['Now','on','spaces']
+ ' '.join['Now','on','spaces']
Note that the list has to be a list of strings to apply join operation.