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| -rw-r--r-- | getting-started-with-lists/script.rst | 39 |
1 files changed, 21 insertions, 18 deletions
diff --git a/getting-started-with-lists/script.rst b/getting-started-with-lists/script.rst index 4e11d0a..628297f 100644 --- a/getting-started-with-lists/script.rst +++ b/getting-started-with-lists/script.rst @@ -22,6 +22,7 @@ .. Author : Amit Internal Reviewer : Anoop Jacob Thomas <anoop@fossee.in> External Reviewer : + Language Reviewer : Bhanukiran Checklist OK? : <put date stamp here, if OK> [2010-10-05] .. #[[Anoop: Slides contain only outline and summary @@ -44,9 +45,9 @@ structure called lists. We will learn :: * Append elements to 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 the order has a meaning. +List is a compound data type, it can contain data of mutually +different datatypes. List is also a sequence data type, all the +elements are arranged in a given order. .. #[[Anoop: "all the elements are in order and **there** order has a meaning." - I guess something is wrong here, I am not able to @@ -69,13 +70,13 @@ Lets now see how to define a non-empty list. We do it as,:: 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 be of the same data type. +of comma-separated values (or items) between two square brackets. 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 are -integer and float. Thus we can put elements of heterogenous types in -lists including list itself. +previous example 'spam' and 'eggs' are strings whereas 100 and 1.234 are +integer and float respectively. Thus we can put elements of different types in +lists including lists itself. This property makes lists heterogeneous +data structures. .. #[[Anoop: the sentence "Thus list themselves can be one of the element types possible in lists" is not clear, rephrase it.]] @@ -84,9 +85,10 @@ Example :: listinlist=[[4,2,3,4],'and', 1, 2, 3, 4] -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. :: +We access an element of a list using its corresponding index. Index of +the first element of a list is 0. So for the 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] @@ -112,9 +114,9 @@ In python negative indices are used to access elements from the end:: 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. +and -4 gives the fourth from the last which, in this case, is the first element. -We can append elements to the end of a list using append command. :: +We can append elements to the end of a list using the method append. :: nonempty.append('onemore') nonempty @@ -134,10 +136,10 @@ 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. +As we can see nonempty is appended with 'onemore' and 6 at the end. Using len function we can check the number of elements in the list -nonempty. In this case it 6 :: +nonempty. In this case it is 6 :: len(nonempty) @@ -175,11 +177,12 @@ experiment. :: nonempty 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 therefore `remove` removes the first occurence of the element in the sequence and leaves others untouched. -One should remember this that while del removes by index number. -Remove , removes on the basis of content being passed so if :: +One should remember this that while del removes by index number, +`remove` removes on the basis of content being passed on. For instance +if :: k = [1,2,1,3] del([k[2]) |