Lesson-3: Lists

This blog assumes that you have a Linux machine with Python already installed. 

If you don't, then you can use an AWS cloud based image that has Python. For guidance refer to my blog

I am using Python 2.7 for this tutorial.

LISTS

Lists are Python's arrays. 

1. They are MUTABLE; meaning the contents of a list can be changed. 

2. They can hold objects of different data types

Example Program-4:

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#!/bin/python

list1 = [12,45,"Mahatma",'Gandhi',5.6]

print "\n list1 = ", list1

# The list reference starts at 0

print "\n list1[0] =",list1[0]

# This is how you can change the value of a list

list1[2] = 'Mohan Das'

print "\n Updated list1 = ", list1

# This is how you remove an object from the list

# using pop() you can remove 1 item

list1.pop(1)

print "\n Updated list1 after deletion of an item = ", list1

#using del() you can delete a range of items

del list1[1:3]

print "\n Updated list1 after deletion of a few more items = ", list1

# length of the list can be obtains with len()

print "\n Current length of list1 = ",len(list1)

# Extend the list as follows

list1 = list1+[7.6,"Soccer",9]

print "\n list1 after extension = ", list1

# Check this out

list1 = list1 * 3

print "\n latest list1=", list1, "\n"

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EXERCISE-2

Write a program that 

1. Has two lists. 

2. List1 has 5 objects.

3. List2 has 6 objects.

4. Concatenate both lists to form List3

5. Delete the last object from List3.

6. Print List3 and its current length. 

7. Delete the middle 3 items from List3.

8. Print List3 and its current length. 
9. Compare List1 and List3 and print results.