Python/C3/Getting-started-with-lists/English-timed - Revision history

PoojaMoolya at 05:48, 27 March 2017

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PoojaMoolya at 12:11, 20 February 2017

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Gaurav at 07:29, 10 July 2014

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Sneha at 06:11, 15 March 2013

2013-03-15T06:11:09Z

Sneha at 09:18, 14 March 2013

2013-03-14T09:18:08Z

Sneha at 07:21, 12 March 2013

2013-03-12T07:21:03Z

Minal: Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello friends and welcome to the tutorial on "Getting started with lists". |- | 0:06 | In this tutorial we will be getting acquainted…'

2013-01-02T10:55:26Z

Created page with '{| border=1 !Timing !Narration |- | 0:00 | Hello friends and welcome to the tutorial on "Getting started with lists". |- | 0:06 | In this tutorial we will be getting acquainted…'

New page

{| border=1
!Timing
!Narration
|-
| 0:00
| Hello friends and welcome to the tutorial on "Getting started with lists".

|-
| 0:06
| In this tutorial we will be getting acquainted with a python data structure called lists. At the end of this tutorial, you will be able to,

# Create lists
# Access list elements
# Append elements to lists
# Delete elements from lists

|-
| 0:23
| So now, List is a compound data type, it can contain data of mutually different data types.

|-
| 0:32
| List is also a sequence data type where all the elements are arranged in a specific order.

|-
|0:36
|Start the ipython interpreter and first create an empty list with no elements.

|-
|0:41
|In command ipython.Then type empty is equal to square brackets.

|-
|0:53
|Then type within brackets empty.

|-
| 0:59
| This is an empty list without any elements.

|-
|1:03
|Lets define a non-empty list as nonempty is equal to within square brackets and in single quotes spam comma within single quotes eggs comma 100 comma 1.234]

|-
| 1:24
| Thus, the simplest way of creating a list is typing out a sequence of comma-separated values (or items) between two square brackets.

|-
|1:34
| As we can see, lists can contain different kinds of data.

|-
|1:37
| In the previous example 'spam' and 'eggs' are strings whereas 100 and 1.234 are integer and float respectively.

|-
|1:48
| Thus, we can put elements of different data types in lists including lists itself.

|-
|1:54
| This property makes lists heterogeneous data structures.

|-
|1:59
| Let us include a list within a list.

|-
| 2:02
| <nowiki>We access an element of a list using its corresponding index. </nowiki>

|-
|2:07
|So type in command listinlist is equal to square brackets [4,2,3,4],'and', 1, 2, 3, 4.

|-
|2:41
|So now we can access an element of a list using its corresponding index.

|-
|2:49
|Index of the first element of a list is 0.

|-
|2:53
|<nowiki>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.</nowiki>

|-
| 3:23
| Pause the video here, try out the following exercise and resume the video.

|-
|3:28
|<nowiki>What happens when you do nonempty[-1].</nowiki>

|-
|3:34
|YOu can switch to terminal and type nonempty -1 in square brackets.

|-
| 3:44
| As you can see you get the data of last element which is 1.234.

|-
| 3:53
| In python negative indices are used to access elements from the end.

|-
| 3:58
| So, -1 gives the last element which is the 4th element , -2 gives second element to last and -4 gives the fourth from the last which, in this case, is the first element.

|-
|4:15
|So type nonempty -1 nonempty[-2] then nonempty -4.

|-
| 4:24
| We can also append elements to the end of a list using the <tt>append</tt> function.

|-
|4:28
|So type nonempty dot append within brackets and single quotes onemore.

|-
|4:41
|We can see an error

|-
|4:46
|Then type nonempty ; then type nonempty dot append within brackets 6.

|-
|5:09
|then again nonempty.

|-
|5:15
| Please, pause the video here, do the exercise and then continue.

|-
|5:21
| 1. What is the syntax to get the element 'and' in the list,listinlist ?

|-
|5:29
|2. How would you get 'and' using negative indices?

|-
| 5:34
| So, the solution is on your screen

|-
| 5:38
|As we can see nonempty is appended with 'onemore' and 6 at the end.

|-
| 5:45
| Let us move further.

|-
|5:47
|We can use <tt>len</tt> function to check the number of elements in the list.

|-
|5:50
| Let us find out the length of the list 'nonempty'.

|-
|5:54
|So type in command len within brackets nonempty .

|-
| 6:05
| Just like we can append elements to a list, we can also remove them.

|-
|6:08
|There are two ways of doing it. One is by using index.

|-
|6:12
|So type del within brackets nonempty and square brackets 1.

|-
| 6:26
| The function <tt>del</tt> deletes the element at index 1, i.e the second element of the list, 'eggs'.

|-
|6:34
|The other way is removing element by content.

|-
|6:37
| Lets say one wishes to delete 100 from nonempty list.

|-
|6:41
|For this, one could use the function <tt>remove</tt>.

|-
| 6:55
| But what if there were two 100's.

|-
|6:57
| To check that lets do a small experiment.

|-
|7:01
|Now, in command nonempty dot append within brackets and single quotes spam.

|-
|7:11
| Then type nonempty.

|-
|7:15
|Then type nonempty dot remove within brackets and single quotes spam; then type nonempty for the output.

|-
| 7:29
| If we now check, we will see that the first occurence 'spam' is removed and therefore the function ''remove'' removes the first occurence of the element in the sequence and leaves others untouched.

|-
|7:39
|One should remember this, that while <tt>del</tt> removes by index number, ''remove'' removes on the basis of content being passed on.

|-
|7:50
| Let us take an example.

|-
| 7:53
| <nowiki>del gives us [1,2,3].</nowiki>

|-
|7:59
|So type on the terminal k is equal to 1,2 ,1,3 and then type del within brackets and square brackets k and square brackets 2.

|-
| 8:25
| <nowiki>remove will give us [2,1,3].

|-
|8:29
|Since it deletes the first occurrence of what is returned by x[2] which is 1.</nowiki>

|-
|8:37
|So type k dot remove and in brackets x and square brackets 2.

|-
|8:59
|As we have seen an error we have to change x of 2 to k of 2.

|-
| 9:09
| Pause the video here, try out the following exercise and resume the video.

|-
|9:14
|1. Remove the third element from the list, listinlist.

|-
|9:19
|2. Remove 'and' from the list, listinlist.

|-
|9:24
| The solution is on your screen.

|-
|9:29
| This brings us to the end of this tutorial.

|-
| 9:30
| In this tutorial, we have learnt to, Create lists, Access lists using their index numbers, Append elements to list using the function <tt>append</tt>.

|-
|9:40
| Delete Element from lists by specifying the index number of the element to be deleted in the <tt>del</tt> function.

|-
|9:47
|Then,Delete element from list by content using <tt>remove</tt> function and final one is Find out the list length using <tt>len</tt> function.

|-
| 9:59
| Here are some self assessment questions for you to solve

|-
|10:02
|1. How do you create an empty list?

|-
|10:05
|2. Can you have a list inside a list ?

|-
|10:09
|3. How would you access the end of a list without finding its length?

|-
| 10:15
| And the answers,

|-
|10:18
|1. We create an empty list just by leaving the space inside the square brackets empty.<br/> <nowiki>empty=[]</nowiki>

|-
|10:30
|2. Yes.

|-
|10:34
|List can contain all the other data types, including list.

|-
|10:44
| Here is an example<br/> <nowiki>list_in_list=[2.3,[2,4,6],'string,'all datatypes can be there']</nowiki>

|-
|10:56
|3. Using negative indices, we can access the list from the end using negative indices.

|-
|11:04
| This is an example<br/> <nowiki>nonempty = ['spam', 'eggs', 100, 1.234]</nowiki> <nowiki>nonempty[-1]</nowiki>

|-
| 11:15
| Hope you have enjoyed this tutorial and found it useful.

|-
|11:19
|Thank you!

@@ Line 271: / Line 271: @@
 |-
 |09:29
-| This brings us to the end of this tutorial.
+| This brings us to the end of this tutorial. In this tutorial, we have learnt to, Create lists, Access lists using their index numbers, Append elements to list using the function  append
-−
-|-
-| 09:30
-| In this tutorial, we have learnt to, Create lists, Access lists using their index numbers, Append elements to list using the function  append
 |-

@@ Line 9: / Line 9: @@
 |  00:06
 | In this tutorial we will be getting acquainted with a python data structure called lists. At the end of this tutorial, you will be able to,
 Create lists
-# Create lists
+Access list elements
-# Access list elements
+Append elements to lists
-# Append elements to lists
+Delete elements from lists
-# Delete elements from lists
 |-
@@ Line 141: / Line 140: @@
 |-
 |05:21
-| 1. What is the syntax to get the element 'and' in the list,listinlist ?
+|What is the syntax to get the element 'and' in the list,listinlist ?
 |-
 |05:29
-|2. How would you get 'and' using negative indices?
+|How would you get 'and' using negative indices?
-−
-−
 |-
@@ Line 187: / Line 184: @@
 |-
 |  06:26
-| The function del deletes the element at index 1, i.e the second element of the list, 'eggs'.
+|The function del deletes the element at index 1, i.e the second element of the list, 'eggs'.
 |-
@@ Line 262: / Line 259: @@
 |-
 |09:14
-|1. Remove the third element from the list, listinlist.
+|Remove the third element from the list, listinlist.
 |-
 |09:19
-|2. Remove 'and' from the list, listinlist.
+|Remove 'and' from the list, listinlist.
-−
-−
 |-
@@ Line 296: / Line 291: @@
 |-
 |10:02
-|1. How do you create an empty list?
+|How do you create an empty list?
 |-
 |10:05
-|2. Can you have a list inside a list ?
+|Can you have a list inside a list ?
 |-
 |10:09
-|3. How would you access the end of a list without finding its length?
+|How would you access the end of a list without finding its length?
 |-
@@ Line 312: / Line 307: @@
 |-
 |10:18
-|1. We create an empty list just by leaving the space inside the square brackets empty.empty=[]
+|We create an empty list just by leaving the space inside the square brackets empty.empty=[]
 |-
 |10:30
-|2. Yes.
+| Yes.
 |-
@@ Line 328: / Line 323: @@
 |-
 |10:56
-|3. Using negative indices, we can access the list from the end using negative indices.
+| Using negative indices, we can access the list from the end using negative indices.
 |-

@@ Line 33: / Line 33: @@
 |-
 |0:53
-|Then type within brackets empty.
+|Then type empty() within brackets empty.
 |-
@@ Line 41: / Line 41: @@
 |-
 |1:03
-|Lets define a non-empty list as nonempty is equal to  within square brackets and in single quotes spam comma within single quotes eggs comma 100 comma  1.234]
+|Lets define a non-empty list as non empty is equal to  within square brackets and in single quotes spam comma within single quotes eggs comma 100 comma  1.234]
 |-
@@ Line 72: / Line 72: @@
 |-
 |2:07
-|So type in command listinlist is equal to square brackets [4,2,3,4],'and', 1, 2, 3, 4.
+|So type in command non empty,then type  listinlist is equal to square brackets [4,2,3,4],'and', 1, 2, 3, 4.
 |-
 |2:41
-|So now we can access an element of a list using its corresponding index.
+|So now we can access an element of a list using  corresponding index.
 |-
@@ Line 84: / Line 84: @@
 |-
 |2:53
-|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.
+|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.So type in command non empty within [0] then again nonempty[1] then nonempty[3]
 |-
@@ Line 108: / Line 108: @@
 |-
 | 3:58
-| So, -1 gives the last element which is the 4th element , -2 gives second element to last and -4 gives the fourth from the last which, in this case, is the first element.
+| So, -1 gives the last element which is the 4th element , -2 gives second element to last and -4 gives the fourth from the last which, in this case, is the element first .
 |-
@@ Line 116: / Line 116: @@
 |-
 | 4:24
-| We can also append elements to the end of a list using the <tt>append</tt> function.
+| We can also append elements to the end of a list using the append function.
 |-
@@ Line 178: / Line 178: @@
 |-
 |6:08
-|There are two ways of doing it. One is by using index.
+|There are two ways of doing it. One is by using index.We will try let type del{nonempty[1]}
 |-
@@ Line 198: / Line 198: @@
 |-
 |6:41
-|For this, one could use the function remove.
+|For this, one could use the function remove. So type nonempty.remove (100)
 |-
@@ Line 210: / Line 210: @@
 |-
 |7:01
-|Now, in command nonempty dot append within brackets and single quotes spam.
+|Now, in command nonempty dot append within brackets in single quotes spam.
 |-
@@ Line 218: / Line 218: @@
 |-
 |7:15
-|Then type nonempty dot remove within brackets and single quotes spam; then type nonempty for the output.
+|Then type nonempty dot remove within brackets in single quotes spam; then type nonempty for the output.
 |-
 | 7:29
-| If we now check, we will see that the first occurence 'spam' is removed and therefore the function ''remove'' removes the first occurence of the element in the sequence and leaves others untouched.
+| If we now check, we will see that the first occurrence 'spam' is removed and therefore the function ''remove'' removes the first occurence of the element in the sequence and leaves others untouched.
 |-
@@ Line 234: / Line 234: @@
 |-
 |  7:53
-| del gives us [1,2,3].
+|Type del gives us [1,2,3].
 |-
 |7:59
-|So type on the terminal k is equal to 1,2 ,1,3 and then type del within brackets and square brackets k and square brackets 2.
+|So type on the terminal k is equal to 1,2 ,1,3 and then type del within brackets and square brackets k then square brackets 2.
 |-
@@ Line 250: / Line 250: @@
 |-
 |8:37
-|So type k dot remove and in brackets x and square brackets 2.
+|So type k dot remove and in brackets x then square brackets 2.
 |-
@@ Line 258: / Line 258: @@
 |-
 | 9:09
-| Pause the video here, try out the following exercise and resume the video.
+| Pause the video here, try out the following exercise and resume
-−
 |-
 |9:14

@@ Line 69: / Line 69: @@
 |-
 | 2:02
-| <nowiki>We access an element of a list using its corresponding index. </nowiki>
+| We access an element of a list using its corresponding index.
-−
 |-
 |2:07
@@ Line 85: / Line 84: @@
 |-
 |2:53
-|<nowiki>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.</nowiki>
+|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.
 |-
@@ Line 93: / Line 92: @@
 |-
 |3:28
-|<nowiki>What happens when you do nonempty[-1].</nowiki>
+|What happens when you do nonempty[-1].
 |-
@@ Line 163: / Line 162: @@
 |-
 |5:47
-|We can use <tt>len</tt> function to check the number of elements in the list.
+|We can use len function to check the number of elements in the list.
 |-
@@ Line 187: / Line 186: @@
 |-
 |  6:26
-| The function <tt>del</tt> deletes the element at index 1, i.e the second element of the list, 'eggs'.
+| The function del deletes the element at index 1, i.e the second element of the list, 'eggs'.
 |-
@@ Line 199: / Line 198: @@
 |-
 |6:41
-|For this, one could use the function <tt>remove</tt>.
+|For this, one could use the function remove.
 |-
@@ Line 227: / Line 226: @@
 |-
 |7:39
-|One should remember this, that while <tt>del</tt> removes by index number, ''remove'' removes on the basis of content being passed on.
+|One should remember this, that while del removes by index number, ''remove'' removes on the basis of content being passed on.
 |-
@@ Line 235: / Line 234: @@
 |-
 |  7:53
-| <nowiki>del gives us [1,2,3].</nowiki>
+| del gives us [1,2,3].
 |-
@@ Line 243: / Line 242: @@
 |-
 |  8:25
-| <nowiki>remove will give us [2,1,3].
+| remove will give us [2,1,3].
 |-
 |8:29
-|Since it deletes the first occurrence of what is returned by x[2] which is 1.</nowiki>
+|Since it deletes the first occurrence of what is returned by x[2] which is 1.
 |-
@@ Line 281: / Line 280: @@
 |-
 | 9:30
-| In this tutorial, we have learnt to, Create lists, Access lists using their index numbers, Append elements to list using the function <tt>append</tt>.
+| In this tutorial, we have learnt to, Create lists, Access lists using their index numbers, Append elements to list using the function  append
-−
 |-
 |9:40
-| Delete Element from lists by specifying the index number of the element to be deleted in the <tt>del</tt> function.
+| Delete Element from lists by specifying the index number of the element to be deleted in the del function.
 |-
 |9:47
-|Then,Delete element from list by content using <tt>remove</tt> function and final one is Find out the list length using <tt>len</tt> function.
+|Then,Delete element from list by content using remove  function and final one is Find out the list length using  len  function.
 |-
@@ Line 315: / Line 313: @@
 |-
 |10:18
-|1. We create an empty list just by leaving the space inside the square brackets empty.<br/>  <nowiki>empty=[]</nowiki>
+|1. We create an empty list just by leaving the space inside the square brackets empty.empty=[]
 |-
@@ Line 327: / Line 325: @@
 |-
 |10:44
-| Here is an example<br/>  <nowiki>list_in_list=[2.3,[2,4,6],'string,'all datatypes can be there']</nowiki>
+| Here is an example list_in_list=[2.3,[2,4,6],'string,'all datatypes can be there']
 |-
@@ Line 335: / Line 333: @@
 |-
 |11:04
-| This is an example<br/>  <nowiki>nonempty = ['spam', 'eggs', 100, 1.234]</nowiki> <nowiki>nonempty[-1]</nowiki>
+| This is an example nonempty = ['spam', 'eggs', 100, 1.234] nonempty[-1]
 |-