Your First Python Program

What Is It?

What Is Your First Python Program?

Every programmer's journey begins with a simple task: making the computer display a message on the screen. In Python, you do this using the print() function. The print() function is the most basic and most frequently used tool in Python — it takes whatever you give it and displays it as text on the screen.

In this chapter, you will learn everything about the print() function: how to print text (strings), how to print numbers, how to print multiple items on one line, how to use special characters like newline and tab, and how to control the output format using the sep and end parameters. You will also learn about comments — notes that you write in your code for humans to read, which Python completely ignores.

What You Will Learn

• How the print() function works
• Printing strings using single quotes and double quotes
• Printing numbers (integers and decimals)
• Printing multiple values with comma separation
• Escape characters: \n, \t, \\, \", \'
• The sep parameter (custom separator between values)
• The end parameter (custom ending instead of newline)
• Comments: single-line (#) and multi-line (''' ''')
• Running complete programs from a file

Why Does It Matter?

Why Is the print() Function So Important?

You might think that printing text on screen is too simple to be important. But the print() function is one of the most critical tools in a programmer's toolkit, and here is why:

1. It Is How Your Program Communicates

A program that does calculations but never shows the results is useless. The print() function is the primary way your program communicates its output to the user. Whether you are building a calculator, a quiz game, or a data analysis tool, you will use print() to display results, messages, and information.

2. It Is Your Best Debugging Tool

When your program is not working correctly, the first thing experienced programmers do is add print() statements to see what is happening at each step. For example, if a calculation gives the wrong result, you can print the value at each stage to find where it goes wrong. This technique is called print debugging, and you will use it throughout your programming career.

3. It Teaches Fundamental Concepts

Learning print() thoroughly introduces you to several important programming concepts:

• Functions: print() is a function — it has a name, takes arguments (inputs), and performs an action.
• Strings: Text inside quotes is called a string. You will work with strings in every program you ever write.
• Parameters: The sep and end parameters teach you how functions can have optional settings that change their behavior.
• Escape sequences: Special character combinations like \n introduce the concept of encoding special characters.

4. Every Program You Write Will Use It

From your very first program to advanced projects, print() is always there. Even professional developers with decades of experience use print() daily. Mastering it now means you have a solid foundation for everything that follows.

Detailed Explanation

Detailed Explanation

The print() Function

The print() function displays output on the screen (technically, it writes to the standard output, which is usually your terminal or console). The basic syntax is:

print(value)

You can pass one or more values to print(), and it will display them. After printing, it automatically moves to the next line (unless you change this behavior with the end parameter).

Printing Strings (Text)

A string is a sequence of characters (letters, numbers, symbols, spaces) enclosed in quotes. In Python, you can use either single quotes ('...') or double quotes ("...") — both work exactly the same way.

print("Hello, World!")    # Using double quotes
print('Hello, World!')    # Using single quotes — same output

Both produce the exact same output: Hello, World!

When to Use Single vs Double Quotes

Since both work the same, when should you use which? The answer is: use whichever makes your string easier to read.

• If your string contains a single quote (apostrophe), use double quotes on the outside: print("It's a great day")
• If your string contains double quotes, use single quotes on the outside: print('She said "Hello"')
• If your string contains neither, use whichever you prefer (most Python developers prefer double quotes)

Printing Numbers

You can print numbers directly without any quotes:

print(42)       # Prints an integer
print(3.14)     # Prints a decimal number
print(2 + 3)    # Prints the result: 5
print(10 * 7)   # Prints the result: 70

Important difference: print(42) prints the number 42, while print("42") prints the text "42". They look the same on screen, but Python treats them differently internally. The first is a number (you can do math with it), and the second is a string (it is just text).

Printing Multiple Values

You can print multiple values in a single print() call by separating them with commas:

print("My name is", "Aarav")
print("I am", 14, "years old")
print("Score:", 95, "out of", 100)

When you separate values with commas, Python automatically adds a space between them in the output.

Output:

My name is Aarav
I am 14 years old
Score: 95 out of 100

Escape Characters

Sometimes you need to include special characters in a string that you cannot type directly. Python uses the backslash (\) as an escape character — it tells Python that the character after the backslash has a special meaning.

Common Escape Characters

Why Do We Need Escape Characters?

Consider this problem: you want to print She said "Hello". If you write print("She said "Hello""), Python gets confused because it sees the second " and thinks the string has ended. The escape character \" tells Python: "This is not the end of the string — this is a literal double quote character that I want to print."

The sep Parameter

When you print multiple values, Python puts a space between them by default. The sep (separator) parameter lets you change what goes between the values:

print("Aarav", "Sharma", sep="-")        # Output: Aarav-Sharma
print("10", "04", "2026", sep="/")       # Output: 10/04/2026
print("A", "B", "C", sep=" -> ")         # Output: A -> B -> C
print("Hello", "World", sep="")           # Output: HelloWorld (no space)
print("one", "two", "three", sep="\n")   # Prints each on a new line

The end Parameter

By default, every print() call ends with a newline character — this is why each print() starts its output on a new line. The end parameter lets you change what comes at the end:

# Default behavior (end="\n"):
print("Hello")
print("World")
# Output:
# Hello
# World

# Custom end:
print("Hello", end=" ")
print("World")
# Output: Hello World (both on same line with a space between)

The end parameter is useful when you want to print multiple things on the same line using separate print() calls.

Comments in Python

Comments are notes written inside your code that Python completely ignores. They exist only for humans — to explain what the code does, why a certain approach was chosen, or to temporarily disable a line of code.

Single-Line Comments (#)

Use the hash symbol (#) to write a comment. Everything after # on that line is ignored by Python:

# This is a comment — Python ignores this line
print("Hello")  # This is an inline comment

# The next line calculates the sum
print(5 + 3)     # Result: 8

Multi-Line Comments (Triple Quotes)

For longer comments that span multiple lines, you can use triple quotes ('''...''' or """..."""):

'''
This is a multi-line comment.
It can span as many lines as you need.
Python treats this as a string but since
it is not assigned to any variable, it is ignored.
'''
print("Hello, World!")

Technically, triple-quoted strings are not "true" comments — they are strings that are not assigned to anything, so Python evaluates them but discards the result. However, they are commonly used as multi-line comments by Python developers.

Why Write Comments?

• For yourself: When you come back to your code after a month, comments remind you what each part does.
• For others: If someone else reads your code, comments help them understand your logic.
• For debugging: You can "comment out" a line of code (add # before it) to temporarily disable it without deleting it.

Running Programs from a File

In the previous chapter, you learned how to create and run .py files. Here is the complete workflow again:

1. Open your code editor (IDLE, VS Code, etc.).
2. Write your program — for example, multiple print() statements.
3. Save the file with a .py extension (e.g., greetings.py).
4. Run the file (F5 in IDLE, or python greetings.py in the terminal).

When you run a file, Python executes all the lines from top to bottom, one at a time. If there is an error on any line, execution stops at that line and shows an error message.

Code Examples

print("Hello, World!")

print("Hello, World!")      # Double quotes
print('Hello, World!')      # Single quotes - same result

# Use double quotes when string has an apostrophe:
print("It's a beautiful day")

# Use single quotes when string has double quotes:
print('She said "Welcome" to everyone')

print(42)           # An integer
print(3.14)         # A decimal (float)
print(7 + 8)        # Addition: 15
print(100 - 37)     # Subtraction: 63
print(6 * 9)        # Multiplication: 54
print(45 / 5)       # Division: 9.0 (always gives decimal)
print(2 ** 10)      # Power: 1024

# Number vs string:
print(50)           # This is a number
print("50")         # This is text (a string)

print("My name is", "Ananya")
print("I am", 13, "years old")
print("Marks in Maths:", 95, "out of", 100)
print("Sum of 5 and 3 is", 5 + 3)
print("Total students:", 30 + 15 + 20)

# Newline: \n moves to next line
print("Line 1\nLine 2\nLine 3")
print()  # Empty line for spacing

# Tab: \t adds horizontal spacing
print("Name\tAge\tCity")
print("Rohit\t14\tMumbai")
print("Sneha\t13\tDelhi")
print()

# Backslash: \\ prints a single \
print("File path: C:\\Users\\Priya\\Documents")

# Quotes inside strings:
print("He said \"Python is fun\"")
print('It\'s a great language')

# sep changes the separator between values
print("Aarav", "Sharma", sep="-")
print(25, "04", 2026, sep="/")
print("A", "B", "C", "D", sep=" -> ")
print("Hello", "World", sep="***")
print()

# end changes what comes after the printed text
print("Loading", end="")
print(".", end="")
print(".", end="")
print(".")

print("Name:", end=" ")
print("Diya")

# Combining sep and end
print(1, 2, 3, sep=", ", end=" ...done!\n")

# This is a single-line comment
# Python ignores everything after the # symbol

print("Hello!")  # This is an inline comment

# You can use comments to temporarily disable code:
# print("This line will NOT run")
print("This line WILL run")

'''
This is a multi-line comment.
It uses triple single quotes.
Useful for longer explanations.
'''

"""
You can also use triple double quotes
for multi-line comments.
"""

print("Program complete!")

# Student Report Card Generator
# Author: Riya Patel
# Date: April 2026

'''
This program prints a formatted report card
using print(), escape characters, and sep/end.
'''

print("========================================")
print("        STUDENT REPORT CARD")
print("========================================")
print()
print("Name:\tRiya Patel")
print("Class:\t9th Standard")
print("Roll No:\t42")
print()
print("Subject", "Marks", sep="\t\t")
print("-------", "-----", sep="\t\t")
print("Maths", "95", sep="\t\t")
print("Science", "88", sep="\t\t")
print("English", "92", sep="\t\t")
print("Hindi", "85", sep="\t\t")
print("Computer", "98", sep="\t\t")
print()
print("Total:", 95 + 88 + 92 + 85 + 98, "out of 500")
print("Result:", end=" ")
print("PASS")
print("========================================")

Common Mistakes

print "Hello, World!"

print("Hello, World!")

print("Hello, World!')
print('Welcome to Python")

print("Hello, World!")
print('Welcome to Python')

print(Hello World)

print("Hello World")

print("Hello/nWorld")
print("Name/tAge")

print("Hello\nWorld")
print("Name\tAge")

print("A", "B", sep = "-")    # Spaces around = (works but not recommended)
print("Hello" sep=",")          # Missing comma before sep
print("Hi", sep:"-")            # Using colon instead of equals

print("A", "B", sep="-")
print("Hello", "World", sep=",")
print("Hi", "Bye", sep="-")

print("C:\new_folder\test")

print("C:\\new_folder\\test")
# Or use a raw string:
print(r"C:\new_folder\test")

Summary