Python provides built-in functions for taking user input and displaying output.

• input(): Used for taking user input.
• print(): Used for displaying output.

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1. Taking Input Using input()

The input() function allows the user to enter data. By default, it treats input as a string.

Syntax:

variable = input("Message to user: ")

Example 1: Taking User Input

name = input("Enter your name: ")
print("Hello,", name)

Output:

Enter your name: Alice
Hello, Alice

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2. Converting Input Data Type

Since input() always returns a string, you must convert it for numeric calculations.

Example 2: Taking Integer Input

age = int(input("Enter your age: "))
print("Next year, you will be", age + 1)

Output:

Enter your age: 25
Next year, you will be 26

• int(input()) converts the input to an integer.

Example 3: Taking Float Input

price = float(input("Enter the price: "))
print("Total price with tax:", price * 1.1)

Output:

Enter the price: 100.5
Total price with tax: 110.55

• float(input()) converts the input to a floating-point number.

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3. Displaying Output Using print()

The print() function outputs data to the console.

Syntax:

print(value1, value2, ..., sep=" ", end="\n")

• sep: Specifies the separator between values (default: space).
• end: Defines what to print at the end (default: newline).

Example 4: Basic Output

print("Hello, World!")

Output:

Hello, World!

Example 5: Printing Multiple Values

name = "Alice"
age = 25
print("Name:", name, "Age:", age)

Output:

Name: Alice Age: 25

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4. Formatting Output

Python offers several ways to format output.

(a) Using f-strings (Python 3.6+)

name = "Alice"
age = 25
print(f"My name is {name} and I am {age} years old.")

Output:

My name is Alice and I am 25 years old.

(b) Using format() Method

name = "Alice"
age = 25
print("My name is {} and I am {} years old.".format(name, age))

Output:

My name is Alice and I am 25 years old.

(c) Using % Formatting (Old Method)

name = "Alice"
age = 25
print("My name is %s and I am %d years old." % (name, age))

Output:

My name is Alice and I am 25 years old.

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5. Customizing print() Output

(a) Changing Separator (sep)

print("Apple", "Banana", "Cherry", sep=", ")

Output:

Apple, Banana, Cherry

(b) Changing End Character (end)

print("Hello", end=" ")
print("World!")

Output:

Hello World!

• The second print() appears on the same line because end=" " prevents a new line.

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6. Printing Special Characters

Python uses escape sequences for special characters.

Example 6: Using Escape Sequences

print("Hello\nWorld!")  # Newline
print("Tab\tSpace")  # Tab space
print("This is a backslash: \\")  # Backslash
print("She said, \"Hello!\"")  # Double quotes inside string

Output:

Hello
World!
Tab    Space
This is a backslash: \
She said, "Hello!"

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7. Printing to a File

You can redirect output to a file using the file parameter.

Example 7: Writing Output to a File

with open("output.txt", "w") as file:
    print("Hello, File!", file=file)

• This creates a file output.txt and writes "Hello, File!" to it.

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Conclusion

• input() takes user input as a string.
• Convert input using int() or float() if needed.
• print() displays output with options like sep and end.
• Use f-strings or format() for formatted output.
• Escape sequences handle special characters like \n, \t, and \".
• Output can be redirected to a file.