Python is a powerful and easy-to-learn programming language used for web development, data science, AI, and automation. It is popular because of its simple syntax, large library support, and strong community. Python works on all platforms and is highly demanded in the tech industry.
print() Function in Python?
The print() function in Python is used to display information on the screen.
It’s one of the most commonly used functions — perfect for showing text, numbers, and results of calculations.
print("Hello, Python Learners!")
🧠 Explanation: The message inside the quotation marks will appear on the screen when the program runs.
print(25)
print(10 + 5)
You can print numbers directly or display the result of a calculation.
You can use commas , to print several things at once:
name = "Bright"
age = 18
print("My name is", name, "and I am", age, "years old.")
Escape characters help format your output.
For example:
\n = new line, \t = tab space.
print("Python is fun!\nLet's keep learning.")
print("Name:\tBright")
Tip: The print() function is great for debugging and checking your program's output.
Installing Python is the first step to start coding. Follow these steps to install it on your computer:
python --versionIf you see a version number like Python 3.x.x, congratulations! Python is successfully installed 🎉
Here’s a short video to guide you step-by-step through the installation process:
In Python, a string is a sequence of characters enclosed in quotes.
You can use either single quotes (' ') or double quotes (" ") to create a string.
# Using single quotes
name = 'Bright'
# Using double quotes
greeting = "Hello, world!"
# Printing strings
print(name)
print(greeting)
Strings are one of the most commonly used data types in Python. You can use them to store text like names, sentences, or even entire paragraphs.
You can perform many operations on strings, such as joining, slicing, and changing case:
text = "Python Programming"
# Accessing characters
print(text[0]) # P
# Slicing
print(text[0:6]) # Python
# Changing to upper case
print(text.upper()) # PYTHON PROGRAMMING
# Combining strings
first = "Hello"
second = "Python"
print(first + " " + second) # Hello Python
Tip: Strings are immutable, meaning once created, their characters cannot be changed directly.
A function in Python is a block of code that performs a specific task. Functions help you organize your code and avoid repetition. You can define a function once and use (or "call") it many times.
In Python, you define a function using the def keyword, followed by the function name and parentheses ().
def greet():
print("Hello, welcome to Python!")
To run this function, you just need to call it:
greet()
You can pass information into a function using parameters. Parameters let your function work with different inputs.
def greet_user(name):
print("Hello, " + name + "!")
# Calling the function
greet_user("Bright")
greet_user("Ama")
Some functions send back a result using the return keyword.
def add_numbers(a, b):
return a + b
# Using the returned value
result = add_numbers(5, 3)
print("The sum is:", result)
Tip: Functions make your code easier to read, reuse, and debug.
In Python, there are two main types of functions:
These are functions that come pre-installed with Python. You can use them anytime without defining them yourself.
# Some common built-in functions
print("Hello, Python!") # Displays text on the screen
len("Bright") # Returns length of a string
type(25) # Returns the data type of the value
max(5, 10, 15) # Returns the largest number
min(5, 10, 15) # Returns the smallest number
sum([1, 2, 3, 4, 5]) # Adds all the numbers in a list
These built-in functions make coding easier and faster because you don’t have to write the logic yourself.
These are functions that you create yourself to perform a specific task.
You define them using the def keyword.
def multiply(a, b):
result = a * b
return result
print(multiply(4, 6)) # Output: 24
You can define as many user-defined functions as you want, depending on your program’s needs.
Summary:
print(), len()).Tip: Use functions to make your code reusable and easy to maintain.
Python provides many built-in functions that make programming easier and faster. You can use them without importing any external library.
print() FunctionDisplays output on the screen.
print("Welcome to Python!")
print(5 + 3)
len() FunctionReturns the number of items in a list, string, or other collection.
name = "Bright"
print(len(name)) # Output: 6
type() FunctionShows the data type of a variable or value.
age = 20
print(type(age)) # Output: <class 'int'>
input() FunctionTakes input from the user.
name = input("Enter your name: ")
print("Hello,", name)
max() and min() FunctionsThese functions find the largest or smallest number in a group.
numbers = [3, 7, 1, 9, 5]
print(max(numbers)) # Output: 9
print(min(numbers)) # Output: 1
sum() FunctionAdds up all numbers in a list.
numbers = [1, 2, 3, 4, 5]
print(sum(numbers)) # Output: 15
round() FunctionRounds a floating-point number to a specific number of decimal places.
pi = 3.14159
print(round(pi, 2)) # Output: 3.14
abs() FunctionReturns the absolute (positive) value of a number.
print(abs(-10)) # Output: 10
sorted() FunctionReturns a sorted list of numbers or strings.
names = ["Ama", "Kofi", "Bright", "Yaw"]
print(sorted(names))
range() FunctionGenerates a sequence of numbers, often used with loops.
for i in range(5):
print(i)
# Output: 0 1 2 3 4
Tip: You can explore more built-in functions by typing help('builtins') in your Python shell.
A variable in Python is used to store data that can be used later in your program. Think of a variable as a container that holds a value — like a box that stores information.
You create a variable by giving it a name and assigning it a value using the = sign.
name = "Bright"
age = 20
height = 1.75
print(name)
print(age)
print(height)
In this example:
name stores a string value ("Bright")age stores an integer value (20)height stores a floating-point value (1.75)_).Name and name are different).
# ✅ Valid variable names
user_name = "Ama"
score = 90
_age = 25
# ❌ Invalid variable names
2name = "Bright" # Starts with a number
user-name = "Ama" # Contains a hyphen
class = "Python" # 'class' is a reserved keyword
You can update a variable’s value by assigning it again.
language = "Java"
language = "Python"
print(language) # Output: Python
Python allows you to assign values to multiple variables in one line.
x, y, z = 5, 10, 15
print(x, y, z)
=).Tip: Use clear variable names that describe their purpose, like student_name or total_score.
In Python, data types are the different kinds of values that can be stored in a variable. They tell Python what kind of data is being handled — like numbers, text, or lists.
# Integer
age = 18
# Float
price = 25.99
# String
name = "Bright"
# Boolean
is_student = True
# List
fruits = ["apple", "banana", "cherry"]
# Tuple
colors = ("red", "green", "blue")
# Dictionary
person = {"name": "Ama", "age": 25}
# Set
unique_numbers = {1, 2, 3, 4}
You can check the type of any value using the type() function:
print(type(age)) # Output: <class 'int'>
print(type(name)) # Output: <class 'str'>
print(type(fruits)) # Output: <class 'list'>
Tip: Knowing data types helps you store and process information correctly in your programs.
The input() function in Python allows users to type information while a program is running. It helps make your programs more interactive by collecting data directly from the user.
name = input("Enter your name: ")
print("Hello, " + name + "!")
🧠 Explanation:
The program displays the message inside the quotes ("Enter your name: ")
and waits for the user to type something.
Whatever the user types is stored in the variable name.
The input() function always returns data as a string.
If you need a number, you must convert it using int() or float().
age = int(input("Enter your age: "))
print("You will be", age + 1, "next year.")
name = input("What is your name? ")
country = input("Where are you from? ")
print("Hello", name, "from", country + "!")
Tip: Always convert user input to the right data type if you plan to use it in calculations.
Comments in Python are lines in your code that are ignored by the computer. They are used to explain what your code does or to make notes for yourself or others.
Use the # symbol to write a comment on one line.
# This is a single-line comment
print("Hello, Python!") # This prints a message
Python does not have a special symbol for multi-line comments,
but you can use triple quotes ''' ... ''' or """ ... """ to write comments on multiple lines.
'''
This is a multi-line comment.
You can write as many lines as you want here.
'''
print("Learning Python is fun!")
Writing clear comments helps others (and your future self) understand your code faster.
Conditional statements let your program make decisions. They check if a condition is True or False and then run specific code depending on the result.
if Statement
The if statement runs a block of code only if a condition is true.
age = 18
if age >= 18:
print("You are an adult.")
if...else Statement
Use else to run code when the if condition is false.
age = 15
if age >= 18:
print("You can vote.")
else:
print("You are too young to vote.")
if...elif...else Statement
Use elif (short for "else if") to check multiple conditions.
score = 75
if score >= 90:
print("Excellent!")
elif score >= 70:
print("Good job!")
elif score >= 50:
print("You passed.")
else:
print("You failed.")
if Statements
You can put an if statement inside another to check multiple levels of conditions.
age = 20
country = "Ghana"
if country == "Ghana":
if age >= 18:
print("You can vote in Ghana.")
else:
print("You are too young to vote.")
Tip: Use indentation (spaces) carefully in Python — it shows which code belongs to which condition.
Loops in Python are used to repeat a block of code multiple times. They help you run the same code again and again without writing it many times.
for Loop
The for loop is used to iterate over a sequence such as a list, tuple, string, or range.
# Loop through a list
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
print(fruit)
# Using range() to loop numbers
for i in range(5):
print("Number:", i)
while Loop
The while loop keeps running as long as a condition is True.
count = 1
while count <= 5:
print("Counting:", count)
count += 1
break Statement
The break statement stops a loop even if the condition is still true.
for num in range(10):
if num == 5:
break
print(num)
continue Statement
The continue statement skips the rest of the code in the loop for that iteration and goes to the next one.
for num in range(6):
if num == 3:
continue
print(num)
else in Loops
The else block in a loop runs only when the loop finishes normally (without a break).
for i in range(3):
print(i)
else:
print("Loop finished!")
Tip: Loops make your code efficient — use them to process lists, data, or repeat tasks automatically.