Python Programming Exercises: Sequences

Below are ten Python programming exercises that demonstrate various operations and use cases for sequences in Python, including strings, lists, tuples, and ranges.

Exercise 1: Accessing Elements in a List

Problem: Write a program access_element.py to create a list of integers from 1 to 5 and print the third element.

# Exercise 1: Accessing Elements in a List
# Use access_element.py
my_list = [1, 2, 3, 4, 5]
print(f"The third element is: {my_list[2]}")
        

Explanation: This program creates a list my_list and accesses the third element using zero-based indexing.

Sample Output:

c:\demo>python access_element.py
The third element is: 3
c:\demo>
    

Exercise 2: Slicing a String

Problem: Write a program slice_string.py to slice a string "Hello, World!" to extract and print the word "World".

# Exercise 2: Slicing a String
# Use slice_string.py
my_string = "Hello, World!"
print(f"Sliced string: {my_string[7:12]}")
        

Explanation: This program uses slicing to extract characters from index 7 to 11 in my_string.

Sample Output:

c:\demo>python slice_string.py
Sliced string: World
c:\demo>
    

Exercise 3: Concatenating Two Lists

Problem: Write a program concatenate_lists.py to concatenate two lists [1, 2, 3] and [4, 5, 6] and print the result.

# Exercise 3: Concatenating Two Lists
# Use concatenate_lists.py
list1 = [1, 2, 3]
list2 = [4, 5, 6]
result = list1 + list2
print(f"Concatenated list: {result}")
        

Explanation: This program concatenates two lists using the + operator and prints the resulting list.

Sample Output:

c:\demo>python concatenate_lists.py
Concatenated list: [1, 2, 3, 4, 5, 6]
c:\demo>
    

Exercise 4: Reversing a Tuple

Problem: Write a program reverse_tuple.py to reverse a tuple (10, 20, 30) and print the result.

# Exercise 4: Reversing a Tuple
# Use reverse_tuple.py
my_tuple = (10, 20, 30)
reversed_tuple = my_tuple[::-1]
print(f"Reversed tuple: {reversed_tuple}")
        

Explanation: This program reverses the tuple my_tuple using slicing with a step of -1.

Sample Output:

c:\demo>python reverse_tuple.py
Reversed tuple: (30, 20, 10)
c:\demo>
    

Exercise 5: Iterating Over a String

Problem: Write a program iterate_string.py to iterate over each character in the string "Python" and print them one by one.

# Exercise 5: Iterating Over a String
# Use iterate_string.py
my_string = "Python"
for char in my_string:
    print(char)
        

Explanation: This program uses a for loop to iterate over each character in my_string and print them individually.

Sample Output:

c:\demo>python iterate_string.py
P
y
t
h
o
n
c:\demo>
    

Exercise 6: Counting Occurrences in a List

Problem: Write a program count_occurrences.py to count the number of times the number 3 appears in the list [1, 2, 3, 4, 3, 5, 3].

# Exercise 6: Counting Occurrences in a List
# Use count_occurrences.py
my_list = [1, 2, 3, 4, 3, 5, 3]
count = my_list.count(3)
print(f"The number 3 appears {count} times.")
        

Explanation: This program uses the count() method to count the occurrences of 3 in my_list.

Sample Output:

c:\demo>python count_occurrences.py
The number 3 appears 3 times.
c:\demo>
    

Exercise 7: Finding the Maximum in a List

Problem: Write a program find_max.py to find and print the maximum value in the list [23, 1, 45, 34, 7].

# Exercise 7: Finding the Maximum in a List
# Use find_max.py
my_list = [23, 1, 45, 34, 7]
max_value = max(my_list)
print(f"The maximum value is: {max_value}")
        

Explanation: This program uses the max() function to find the maximum value in my_list.

Sample Output:

c:\demo>python find_max.py
The maximum value is: 45
c:\demo>
    

Exercise 8: Creating a List Using Range

Problem: Write a program create_even_list.py to create a list of even numbers from 2 to 20 using the range() function.

# Exercise 8: Creating a List Using Range
# Use create_even_list.py
even_numbers = list(range(2, 21, 2))
print(f"Even numbers: {even_numbers}")
        

Explanation: This program uses the range() function to generate even numbers from 2 to 20 and converts them into a list.

Sample Output:

c:\demo>python create_even_list.py
Even numbers: [2, 4, 6, 8, 10, 12, 14, 16, 18, 20]
c:\demo>
    

Exercise 9: Finding the Index of an Element

Problem: Write a program find_index.py to find the index of the value 45 in the list [23, 1, 45, 34, 7].

# Exercise 9: Finding the Index of an Element
# Use find_index.py
my_list = [23, 1, 45, 34, 7]
index = my_list.index(45)
print(f"The index of 45 is: {index}")
        

Explanation: This program uses the index() method to find the position of the value 45 in my_list.

Sample Output:

c:\demo>python find_index.py
The index of 45 is: 2
c:\demo>
    

Exercise 10: Zipping Two Lists

Problem: Write a program zip_lists.py to combine two lists [1, 2, 3] and ['a', 'b', 'c'] into a list of tuples using the zip() function.

# Exercise 10: Zipping Two Lists
# Use zip_lists.py
list1 = [1, 2, 3]
list2 = ['a', 'b', 'c']
zipped_list = list(zip(list1, list2))
print(f"Zipped list: {zipped_list}")
        

Explanation: This program uses the zip() function to combine list1 and list2 into a list of tuples.

Sample Output:

c:\demo>python zip_lists.py
Zipped list: [(1, 'a'), (2, 'b'), (3, 'c')]
c:\demo>
    

Key Takeaway

These exercises cover various operations on sequences, including indexing, slicing, concatenation, iteration, and more. By working through these examples, you'll gain a deeper understanding of how to manipulate sequences in Python, which is essential for effective programming.