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Diffstat (limited to 'manipulating-lists/script.rst')
| -rw-r--r-- | manipulating-lists/script.rst | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/manipulating-lists/script.rst b/manipulating-lists/script.rst index ba0bfa3..4b4bbf5 100644 --- a/manipulating-lists/script.rst +++ b/manipulating-lists/script.rst @@ -11,9 +11,10 @@ .. 3. .. Author : Madhu - Internal Reviewer : + Internal Reviewer : Punch External Reviewer : - Checklist OK? : <put date stamp here, if OK> [2010-10-05] + Language Reviewer : Bhanukiran + Checklist OK? : <16-11-2010, Anand, OK> [2010-10-05] Script ------ @@ -24,10 +25,10 @@ Hello friends. Welcome to this spoken tutorial on Manipulating Lists. {{{ Show the slide containing the outline }}} -We have already learnt a lot about Lists in Python. In this tutorial, -we will learn more about advanced features of Lists in Python. We will -see how to concatenate two lists, details of slicing and striding of -lists, methods to sort and reverse lists. +We have already learnt about Lists in Python. In this tutorial, +we will learn about more advanced features of Lists in Python like how +to concatenate two lists, details of slicing and striding of lists, +methods to sort and reverse lists. {{{ Shift to terminal and start ipython }}} @@ -49,16 +50,16 @@ lists. Let us say I have the list:: primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29] -To obtain the all the primes between 10 and 20 from the above list of +To obtain all the primes between 10 and 20 from the above list of primes we say:: primes[4:8] This gives us all the elements in the list starting from the element -with the index 4 which is 11 in our list upto the element with index 8 +with the index 4, which is 11 in our list, upto the element with index 8 in the list but not including the eigth element. So we obtain a slice starting from 11 upto 19th. It is a very important to remember that -when ever we specify a range of elements in Python the start index is +whenever we specify a range of elements in Python the start index is included and end index is not included. So in the above case, 11 which was the element with the index 4 was included but 23 which was the element with index 8 was excluded. @@ -129,7 +130,7 @@ Please, pause the video here. Do the exercise and then continue. gives us all the multiples of 3 from the list, since every third element in it, starting from 0, is divisible by 3. -The other basic operation that we can perform on list is concatenation +The other basic operation that we can perform on lists is concatenation of two or more lists. We can combine two lists by using the "plus" operator. Say we have @@ -160,7 +161,7 @@ Now the contents of the list ``a`` will be:: a [1, 5, 6, 7, 7, 10] -Since the sort method sorts the list inplace the original list we had +As the sort method sorts the elements of a list, the original list we had is overwritten or replaced. We have no way to obtain the original list back. One way to avoid this is to keep a copy of the original list in another variable and run the sort method on the list. However Python @@ -174,8 +175,7 @@ We can store this sorted list another list variable:: sa = sorted(a) -Similarly to perform certain operations on the list we would like to -reverse the list. Python provides reverse method which again reverses +Python also provides the reverse method which reverses the list inplace:: a = [1, 2, 3, 4, 5] |