Python Data Structures - List

Index/ Python

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Objective

Learn the list data structures in python

Reference

Essentials

• From Byte of Python read the following chapters
  • Data structures - read lists section
• From Dive into Python3, read the following chapters
  • Native data types - Read sections on Lists
• Understand list slicing
  • slicing 1

Checklist

After completing the exercises below, you should be comfortable with

• Using lists

Exercises

Difficulty Level

★☆☆ - Easy
★★☆ - Medium
★★★ - Challenging
★★★★ - Bonu

A - Creating Lists

A1 - Create a list a = [10,20,30,40,50] (★☆☆)
We will use this list for exercises below

A2 print out the size of the list (★☆☆)
Hint: len

A3 - Append 60 to the end of list (★☆☆)
Expected output: (10,20,30,40,50,60)

A4 - insert 5 at the front of list (★☆☆)
Expected output: (5,10,20,30,40,50,60)

A5 - insert 15 at position 2 (between 10,20) (★☆☆)
Expected output: (5,10,15,20,30,40,50,60)

A6 - copy the list a into another list b (★☆☆)

A7 - delete the last element from the copied list b print both to make sure that original list a isn’t affected (★☆☆)
Expected output:
a = [10,20,30,40,50]
b = [10,20,30,40]

A8 - Find the max/min elements in a list (★☆☆)
Hint: min and max

A9 - Sum up all the elements in list (★☆☆)
Hint: sum

B - Accessing/Indexing Lists

Let’s work with list [10,20,30,40,50]

B1 - Print first element in list (★☆☆)
Hint : [0]
Expected answer : 10

B2 - Print the last element of list (★☆☆)
Hint : [-1]
Expected output: 50

B3 - Print elements at index 2-4 (★☆☆)
Expected output: [30, 40, 50]

B4 - Print all elements starting with index 3 (★☆☆)
Hint : [3:] Expected output: [40, 50]

B5 - Print the last 3 elements of list (★☆☆)
Hint : [-3:]
Expected output: [30,40,50]

B6 - Iterate over the list and print one per line (★☆☆)
Hint : for item in list

C - Sorting and Searching

C1 - Create a list of 10 random numbers between 0 and 100 (★★☆)
Hint: random.randint

C2 - Sort the above list (★★☆)
Hint: sort

C3 - Reverse sort the list (★★☆)

C4 - Create a list x=[1,5,10,15,20]. Check if 10 is part of the list (★★☆)
Hint : in
Expected answer : True

C5 - Check to see if 25 is part of the list (★★☆)
Hint : in Expected answer : False

C6 - Create a list of 10 random numbers between 0 and 100. Print all elements higher than 50 (★★☆)

Exercises

Ex-1 - Work with 2 lists (★★☆)

a = [1,5,2,10,7,4,6]
b = [1,4,3]

Print all numbers common to a and b (★★☆)

Print all numbers unique to a (not in b) (★★☆)

Ex-2 - Remove duplicates (★★☆)

a = [3,2,1,5,2,1,6,5]
Remove duplicates from a

EX-3 - Process word list

Print out words in a sentence that are longer than 3

sentence = 'I like to program in Python'

words = sentence.split(' ') # words is a list
print (words)

## TODO : iterate through the word list and print out words that are longer than 3 

More Exercises

• https://www.w3resource.com/python-exercises/list/