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-Hello friends and welcome to the tutorial on Tuples
-
-{{{ Show the slide containing title }}}
-
-{{{ Show the slide containing the outline slide }}}
-
-In this tutorial, we shall learn
-
- * what are tuples
- * their similarities and dissimilarities with lists
- * why are they needed
-
-Let`s get started by defining a tuple. A tuple is defined by enclosing
-parantheses around a sequence of items seperated by commas. It is similar to
-defining a list except that parantheses are used instead of square brackets.
-::
-
- t = (1, 2.5, "hello", -4, "world", 1.24, 5)
- t
-
-defines a tuple. The items in the tuple are indexed using numbers and can be
-accessed by using their position.
-::
-
- t[3]
-
-prints -4 which is the fourth item of the tuple.
-
-::
-
- t[1:5:2]
-
-prints the corresponding slice
-
-This is the behaviour similar as to lists. But the difference can be seen when
-we try to change an element in the tuple.
-::
-
- t[2] = "Hello"
-
-We can see that, it raises an error saying tuple does not support item
-assignment. It only implies that tuples are immutable or in simple words,
-tuples cannot be changed.
-
-But what is the use of tuples!!!
-
-We shall understand that soon. But let us look at a simple problem of swapping
-values.
-
-{{{ Pause here and try out the following exercises }}}
-
-%% 1 %% a = 5 and b = 7. swap the values of a and b
-
-{{{ continue from paused state }}}
-::
-
- a = 5
- b = 7
-
- a
- b
-
-We define the two values
-::
-
- temp = a
- a = b
- b = temp
-
- a
- b
-
-This is the traditional approach
-
-Now let us do it the python way
-::
-
- a
- b
-
- a, b = b, a
-
- a
- b
-
-We see that the values are swapped.
-This idiom works for different datatypes also.
-::
-
- a = 2.5
- b = "hello"
-
- a
- b
-
-Moreover this type of behaviour is straight forward and what you would expect
-should happen naturally.
-
-This is possible because of the immutability of tuples. This process is called
-tuple packing and unpacking.
-
-Let us first see what is tuple packing. Type
-::
-
- 5,
-
-What we see is a tuple with one element.
-::
-
- 5, "hello", 2.5
-
-Now it is a tuple with two elements.
-
-So when we are actually typing two or more elements seperated by commas, those
-elements are packed and a tuple is made from them.
-
-When you type
-::
-
- a, b = b, a
-
-First the values of b and a are packed into a tuple on the right side and then
-unpacked into the variables a and b.
-
-Immutability of tuples ensures that the values are not changed during the
-packing and unpacking.
-
-{{{ Show summary slide }}}
-
-This brings us to the end of the tutorial.
-we have learnt
-
- * How to define tuples
- * The similarities of tuples with lists, like indexing and iterability
- * The immutability of tuples
- * The value swapping idiom in Python
- * packing and unpacking of tuples
-
-{{{ Show the "sponsored by FOSSEE" slide }}}
-
-#[Nishanth]: Will add this line after all of us fix on one.
-This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
-
-Hope you have enjoyed and found it useful.
-Thankyou
-
-.. Author : Nishanth
- Internal Reviewer 1 :
- Internal Reviewer 2 :
- External Reviewer :
-
-Questions
-=========
-
- 1. Define a tuple containing two values. The first being integer 4 and second
- is a float 2.5
-
- Answer: (4, 2.5)
-
- 2. If ``a = (5, "Hello", 3.2)``. what is the value of a[2]
-
- Answer: 3.2
-
- 3. If ``a = 5,`` then what is the type of a
-
- a. int
- #. float
- #. tuple
- #. string
-
- Answer: tuple
-
- 4. if ``a = (2, 3)``. What does ``a[0], a[1] = (3, 4)`` produce
-
- Answer: Error
-
- 5. If ``a = ([2, 3], 4, 5)``. What is the value of ``a`` after doing
- ``a[0].append(6)``
-
- a. ([2, 3, 6], 4, 5)
- #. Raises an error
- #. ([2, 3], 4, 5)
- #. [2, 3, 4, 5, 6]
-
- Answer: ([2, 3, 6], 4, 5)
-
- 6. What does the following code produce::
-
- a = 5
- b = "Hello"
- a, b = b, a
- print a
- print b
-
- Answer: Hello
- 5
-
- 7. ``a = ("hello", "world", 5, 6, 8)``. What is the value of a[1:4]
-
- Answer: ("world", 5, 6)
-
- 8. ``a = (1, 2, 3, 4, 5, 6, 7, 8)``. What is the value of a[1::3]
-
- Answer: (2, 5, 8)
-
-