Learn Python from Scratch 2023: Module 2

Module 2: Basic Programming Concepts

2.1 Variables and data types:

Variables and Data Types In Python, a variable is a container for storing data. There are different data types in Python, including:

• Integer: whole numbers, such as 1, 2, 3
• Float: decimal numbers, such as 3.14, 2.5
• String: text, such as “Hello, World!”
• Boolean: True or False

Here’s an example of creating a variable:

# Integer variable
age = 25

# Float variable
price = 2.99

# String variable
name = "John"

# Boolean variable
is_student = True

2.2: Operators:

Operators are symbols that perform operations on variables and values. There are different types of operators in Python, including:

• Arithmetic operators: +, -, *, /, % (modulus), ** (exponentiation)
• Assignment operators: =, +=, -=, *=, /=, %=
• Comparison operators: == (equal to), != (not equal to), > (greater than), < (less than), >= (greater than or equal to), <= (less than or equal to)
• Logical operators: and, or, not

Here’s an example of using operators:

# Arithmetic operators
a = 10
b = 5
c = a + b    # c = 15
d = a / b    # d = 2.0
e = a % b    # e = 0

# Assignment operators
f = 1
f += 2       # f = 3
f *= 2       # f = 6

# Comparison operators
g = 5
h = 10
print(g == h)    # False
print(g < h)     # True

# Logical operators
i = True
j = False
print(i and j)   # False
print(i or j)    # True
print(not i)     # False

2.3 Control flow (if-else, loops):

Control Flow Control flow refers to the order in which the code is executed. There are different control flow statements in Python, including:

• If statement: executes a block of code if a condition is true
• Else statement: executes a block of code if the condition in the if statement is false
• Elif statement: executes a block of code if the condition in the if statement is false, but another condition is true
• For loop: executes a block of code for each item in a sequence
• While loop: executes a block of code as long as a condition is true

Here’s an example of using control flow statements:

# If statement
x = 10
if x > 5:
    print("x is greater than 5")
else:
    print("x is less than or equal to 5")

# Elif statement
y = 3
if y > 5:
    print("y is greater than 5")
elif y == 5:
    print("y is equal to 5")
else:
    print("y is less than 5")

# For loop
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

# While loop
i = 1
while i < 6:
    print(i)
    i += 1

That’s it for Module 2! By following these steps, you should now have a solid understanding of variables, data types,