Practical Exercises

To practice conditions, loops, and string manipulation, here are some practical exercises to do:

Exercise 1: Counting Characters in a String (Easy)

Objective: Work on string manipulation and loops.

• Write a program that asks the user to enter a string.
• The program must display the number of characters present in the string, excluding spaces.

Instructions:

• Use a for loop to traverse the string.
• Use an if condition to ignore spaces.

Example:

• Input: "Hello world"
• Output: "Number of characters (without spaces): 10"

Exercise 2: Determine Number Parity

Objective: Use loops and conditions.

• Write a program that asks the user to enter a positive integer.
• Then, the program must display all numbers from 0 to this number with an indication if they are even or odd.

Instructions:

• Use a for loop to traverse the range of numbers.
• Use an if...else condition to determine the parity of each number.

Example:

• Input: 5
• Output: "0 is even" "1 is odd" "2 is even" "3 is odd" "4 is even" "5 is odd"

Exercise 3: Strong Password

Objective: Work on conditions and string manipulation.

• Write a program that asks the user to enter a password.
• The program must check if the password is strong according to the following criteria:
  • At least 8 characters.
  • Contains at least one uppercase letter, one lowercase letter, one digit and one special character (for example, !, @, #, $, etc.).
• Display a message indicating if the password is strong or weak.

Instructions:

• Use string methods like isupper(), islower(), isdigit().
• Use if...elif...else conditions to check the criteria.

Example:

• Input: "Passw0rd!"
• Output: "Strong password"

Exercise 4: Calculate the GCD of Two Numbers

Objective: Use loops and conditions to implement a classic algorithm.

• Write a program that asks the user to enter two positive integers.
• Calculate the greatest common divisor (GCD) of these two numbers using Euclid's algorithm.
• Display the result.

Instructions:

• Use a while loop to implement Euclid's algorithm:
  • While the two numbers are not equal, replace the larger of the two with the difference between the two.
• Use conditions to compare the numbers.

Example:

• Input: 48, 18
• Output: "The GCD of 48 and 18 is 6"

Exercise 5: Analyze Word Frequency in a Sentence

Objective: Advanced string manipulation, loops and conditions.

• Write a program that asks the user to enter a sentence.
• The program must count and display the frequency of each word in the sentence.
• Ignore case (uppercase/lowercase) and punctuation marks.

Instructions:

• Use split() to divide the sentence into words.
• Use a dictionary to store the frequency of each word.
• Use loops and conditions to clean words of all punctuation and count their occurrence.

Example:

• Input: "Hello, hello the world! The world is vast."
• Output: "hello: 2" "the: 2" "world: 2" "is: 1" "vast: 1"