Python/C3/Getting-started-with-tuples/English-timed

Timing	Narration
0:00	Hello friends and welcome to the tutorial on "getting started with tuples".
0:05	At the end of the tutorial, you will be able to, Understand of what tuples are. Compare them with lists. Know why they are needed and where to use them.
0:15	Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with lists".
0:21	Let us start our ipython interpreter.
0:23	Type ipython and hit Enter.
0:27	Let's get started by defining a tuple.
0:29	A tuple is defined by enclosing parentheses around a sequence of items separated by commas.
0:39	It is similar to defining a list except that parentheses are used instead of square brackets.
0:45	So type t is equal to within brackets 1, 2.5, "hello",-4, "world", 1.24,5.
1:02	The items in the tuple are indexed using numbers and can be accessed by using their position.
1:10	For example,
1:11	First you must type t
1:18	Then t within square brackets 3.
1:24	It prints -4 which is the fourth item of the tuple.
1:29	Similarly type t within square brackets 1 colon 5 colon 2 and hit Enter.
1:40	It prints the corresponding slice.
1:42	This behaviour is similar to that of lists.
1:46	But the difference can be seen when we try to change an element in the tuple.
1:51	So type t within square brackets 2 is equal to within double quotes Hello, H is capital.
2:05	We can see that, it raises an error saying 'tuple object does not support item assignment'.
2:10	Tuples are immutable, and hence cannot be changed after creation.
2:13	Then, what is the use of tuples?
2:16	We shall understand that soon.
2:19	But let us look at a simple problem of swapping values.
2:24	Pause the video here, try out the following exercise and resume the video.
2:30	Given, a is equal to 5 and b is equal to 7.
2:33	Swap the values of a and b.
2:38	Switch to terminal of solution
2:40	Type a is equal to 5, then b is equal to 7 , then type a and then b, you can see the values.
2:50	We now create a variable say, temp and swap the values using this variable.
2:56	So type temp is equal to a.Then a is equal to b ;then type b is equal to temp.
3:08	Then type a.
3:10	Then b.
3:13	This is the traditional approach
3:16	So let us do it the python way.
3:21	So type a; then b; then a comma b is equal to b comma a.
3:33	then a ; then b gives the output.
3:38	We see that the values are swapped.
3:43	This idiom works for different data-types also.
3:46	So lets type a is equal to 2 point 5; then b within double quotes hello where h is small letter.
3:59	Then a comma b is equal to b comma a.
4:09	Then a; then b.
4:13	Moreover this type of behaviour is something that feels natural and you'd expect to happen.
4:19	This is possible because of the immutability of tuples.
4:22	This process is called tuple packing and unpacking.
4:26	So type 5 comma and hit Enter.
4:37	What we see in the tuple is 1 element.
4:41	So type 5 comma within double quotes hello where h is small letter comma 2.5.
4:57	Now, It is a tuple with 3 elements.
5:03	So when we are actually typing 2 or more elements separated by comma the elements are packed into a tuple.
5:10	When we type a comma b is equal to b comma a first the value of b and a are packed into a tuple from the right side then unpack into the variables a and b.
5:21	Immutability of tuples ensure that values are not changed during the packing and unpacking.
5:29	So This brings us to the end of this tutorial.
5:33	In this tutorial, we have learnt to,
5:35	1. Define tuples.
5:36	2. Understand the similarities of tuples with lists, like indexing and iterability.
5:44	3. Know about the immutability of tuples.
5:48	4. Swap values, the python way.
5:52	5. Understand the concept of packing and unpacking tuples.
5:57	Here are some self assessment questions for you to solve.
6:01	1. Define a tuple containing two values.
6:04	The first being integer 4 and second is a float 2.5
6:08	2. If a = 5, then what is the type of a ?
6:13	The options are int , float, tuple, string.
6:19	The final question the third one is if a = (2, 3)
6:25	What does a[0], a[1] = (3, 4) produce.
6:34	And the answers,
6:38	1. A tuple is defined by enclosing parentheses around a sequence of items separated by commas.
6:44	Hence, we write our tuple as,within brackets 4 comma 2.5.
6:53	2. Since the given data is 5 followed by a comma, it means that it is a tuple
7:01	3. The operation a within square brackets 0, a within square brackets 1 is equal to within brackets 3 comma 4 will result in an error because tuples are immutable.
7:14	Hope you have enjoyed this tutorial and found it useful.
7:17	Thank you!

Contributors and Content Editors

Gaurav, Minal, PoojaMoolya, Sneha