Learning Python

We will be doing this lab inconjuction with the Python lecture. Key concepts will be explained and you will put into practice.

0. Interpreter for Python

• We should not need to do anything for the university machines to run python as this is already part of the PATH, you can run the following commands:

  Terminal

  $ which python
  $ python --version
  $ which pip
  $ pip --version
  

  Output

  

So let's make our first program.

Exercises 1. Hello World

1. Frist we need to create a directory and file, call directory learning_python and create a file in side it called helloworld.py:

   

2. Modify the files content to contain the following:

   Code

   def main():
       print("Hello World!")
       print("Goodbye World!")
   
   if __name__=="__main__":
       main()
   

   

Exercise 2: Variables and Data Types

Instructions:

0. Create a new file called variables.py

1. Create a variable called name and assign it your name as a string.

2. Create a variable called age and assign it your age as an integer.

3. Create a variable called height and assign it your height in meters as a float.

4. Print each variable on a new line.

5. and then run it.

   Code

   name = "Your name"
   age = 25
   height = 1.75
   
   print(name)
   print(age)
   print(height)
   

   Terminal

   $ python variables.py
   > Your name
   > 25
   > 1.75
   

Exercise 3: Basic Operations

Instructions:

0. Create a new file call it basicMaths.py

1. Create two variables, a and b, and assign them any two numbers.

2. Perform and print the results of addition, subtraction, multiplication, and division between a and b.

3. Use the modulus operator to find the remainder of a divided by b and print the result.

4. and then run it.

   Code

   a = 10
   b = 3
   
   print("Addition:", a + b)
   print("Subtraction:", a - b)
   print("Multiplication:", a * b)
   print("Division:", a / b)
   print("Modulus:", a % b)
   

   Terminal

   $ python basicMaths.py
   > Addition: 13
   > Subtraction: 7
   > Multiplication: 30
   > Division: 3.3333333333333335
   > Modulus: 1
   

Exercise 4: Lists and Indexing

Instructions:

0. Create a new file called lists.py

1. Create a list called fruits that contains the following fruits: "apple", "banana", "cherry".

2. Print the first fruit in the list.

3. Add a new fruit "orange" to the list and print the updated list.

4. Remove "banana" from the list and print the list again.

5. and then run it

   Code

   fruits = ["apple", "banana", "cherry"]
   print("First fruit:", fruits[0])
   
   fruits.append("orange")
   print("Updated list:", fruits)
   
   fruits.remove("banana")
   print("List after removing banana:", fruits)
   

   Terminal

   $ python lists.py
   > First fruit: apple
   > Updated list: ['apple', 'banana', 'cherry', 'orange']
   > List after removing banana: ['apple', 'cherry', 'orange']
   

Exercise 5: Conditional Statements

Instructions:

0. Create a file called conditionals.py

1. Write a program that checks if a number is positive, negative, or zero.

2. Assign a value to the variable number and use if, elif, and else to print:

   • "Positive" if the number is greater than 0
   • "Negative" if the number is less than 0
   • "Zero" if the number is exactly 0.

3. and then run it.

4. change 5 to 0 and run again

   Code

   number = 5
   
   if number > 0:
       print("Positive")
   elif number < 0:
       print("Negative")
   else:
       print("Zero")
   

   Terminal

   python conditionals.py
   Positive
   python conditionals.py
   Zero
   

Exercise 6: Loops

Instructions:

0. Create a file called loops.py

1. Write a for loop that prints numbers from 1 to 5.

2. Create a list of your favorite colors and use a for loop to print each color.

3. Write a while loop that prints numbers from 10 down to 1.

4. run the program

   Code

   # For loop to print numbers from 1 to 5
   for i in range(1, 6):
       print(i)
   
   # For loop to print each favorite color
   favorite_colors = ["blue", "green", "red"]
   for color in favorite_colors:
       print(color)
   
   # While loop to print numbers from 10 down to 1
   n = 10
   while n > 0:
       print(n)
       n -= 1
   

   Terminal

   $ python loops.py
   > 1
   > 2
   > 3
   > 4
   > 5
   > blue
   > green
   > red
   > 10
   > 9
   > 8
   > 7
   > 6
   > 5
   > 4
   > 3
   > 2
   > 1
   

Exercise 7: Functions

Instructions:

0. Create a new file called functions.py

1. Write a function called greet that takes a name as a parameter and prints "Hello, <name>!".

2. Write a function square that takes a number as a parameter and returns its square.

3. Test both functions by calling them with sample inputs.

   Code

   def greet(name):
       print(f"Hello, {name}!")
   
   def square(number):
       return number ** 2
   
   # Testing the functions
   greet("Alice")
   print("Square of 4:", square(4))
   

   Terminal

   $ python functions.py
   > Hello, Alice!
   > Square of 4: 16
   

Exercise 8: Dictionaries

Instructions:

0. Create the a file called dictionaries.py

1. Create a dictionary called student with keys: name, age, and courses. Assign appropriate values to each.

2. Print the student's name and age.

3. Add a new key graduation_year with a sample year and print the updated dictionary.

4. and run it.

   Code

   student = {
       "name": "Your name",
       "age": 21,
       "courses": ["Subject1", "Subject2"]
   }
   
   print("Name:", student["name"])
   print("Age:", student["age"])
   
   student["graduation_year"] = 2025
   print("Updated student dictionary:", student)
   

   Terminal

   $ python dictionaries.py
   > Name: Your name
   > Age: 21
   > Updated student dictionary: {'name': 'Your name', 'age': 21, 'courses': ['Subject1', 'Subject2'], 'graduation_year': 2025}