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

Time	Narration
00:00	Hello friends and welcome to the tutorial on "getting started with tuples".
00:05	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.
00:15	Before beginning this tutorial,we would suggest you to complete the tutorial on "Getting started with lists".
00:21	Let us start our ipython interpreter.
00:23	Type ipython and hit Enter.
00:27	Let's get started by defining a tuple.
00:29	A tuple is defined by enclosing parentheses around a sequence of items separated by commas.
00:39	It is similar to defining a list except that parentheses are used instead of square brackets.
00:45	So type t is equal to within brackets 1, 2.5, "hello",-4, "world", 1.24,5.
01:02	The items in the tuple are indexed using numbers and can be accessed by using their position.
01:10	For example,
01:11	First you must type t
01:18	Then type t within square brackets 3.
01:24	It prints -4 which is the fourth item of the tuple.
01:29	Similarly type t within square brackets 1 colon 5 colon 2 and hit Enter.
01:40	It prints the corresponding slice.
01:42	This behaviour is similar to that of lists.
01:46	But the difference can be seen when we try to change an element in the tuple.
01:51	So type t within square brackets 2 is equal to in double quotes Hello, H is capital.
02:05	We can see that, it raises an error saying 'tuple object does not support item assignment'.
02:10	Tuples are immutable, and hence cannot be changed after creation.
02:13	Then, what is the use of tuples?
02:16	We shall understand that soon.
02:19	But let us look at a simple problem of swapping values.
02:24	Pause the video here, try out the following exercise and resume the video.
02:30	Given, a is equal to 5 and b is equal to 7.
02:33	Swap the values of a and b.
02:38	Switch to terminal for solution
02:40	Type a is equal to 5, then b is equal to 7 , then type a and then b, you can see the values.
02:50	We now create a variable say, temp and swap the values using this variable.
02:56	So type temp is equal to a.Then a is equal to b ;then type b is equal to temp.
03:08	Then type a.
03:10	Then b.
03:13	This is the traditional approach
03:16	So let us do it the python way.
03:21	So type a; then b; then a comma b is equal to b comma a.
03:33	then a ; then b to see the output.
03:38	We see that the values are swapped.
03:43	This idiom works for different data-types also.
03:46	So lets type a is equal to 2 point 5; then b within double quotes hello where h is small letter.
03:59	Then a comma b is equal to b comma a.
04:09	Then a; then b.
04:13	Moreover this type of behavior is something that feels natural and you'd expect to happen.
04:19	This is possible because of the immutability of tuples.
04:22	This process is called tuple packing and unpacking.
04:26	So type 5 comma to see what is tuple packing
04:37	What we see in the tuple is 1 element.
04:41	So type 5 comma within double quotes hello where h is small letter comma 2.5.
04:57	Now, It is a tuple with 3 elements.
05:03	So when we are actually typing 2 or more elements separated by comma the elements are packed into a tuple.
05:10	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.
05:21	Immutability of tuples ensure that values are not changed during the packing and unpacking.
05:29	So This brings us to the end of this tutorial.
05:33	In this tutorial, we have learn't to,
05:35	1. Define tuples.
05:36	2. Understand the similarities of tuples with lists, like indexing and iterability.
05:44	3. Know about the immutability of tuples.
05:48	4. Swap values, the python way.
05:52	5. Understand the concept of packing and unpacking tuples.
05:57	Here are some self assessment questions for you to solve.
06:01	1. Define a tuple containing two values.
06:04	The first being integer 4 and second is a float 2.5
06:08	2. If a = 5, then what is the type of a ?
06:13	The options are int , float, tuple, string.
06:19	The final question the third one is if a = (2, 3)
06:25	What does a[0], a[1] = (3, 4) produce.
06:34	And the answers,
06:38	1. A tuple is defined by enclosing parentheses around a sequence of items separated by commas.
06:44	Hence, we write our tuple as,within brackets 4 comma 2.5.
06:53	2. Since the given data is 5 followed by a comma, it means that it is a tuple
07:01	3. The operation a in square brackets 0, a in square brackets 1 is equal to in brackets 3 comma 4 will result in an error because tuples are immutable.
07:14	Hope you have enjoyed this tutorial and found it useful.
07:17	Thank you!

Contributors and Content Editors

Gaurav, Minal, PoojaMoolya, Sneha