Taking Input and Displaying Output in Python

 

Taking Input and Displaying Output in Python

In Python, you can easily take input from users and display output using built-in functions. This section covers how to take user input with the input() function and how to display output using the print() function.

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1. Taking Input with input()

The input() function is used to take input from the user. When called, it pauses the program and waits for the user to enter some data. Once the user hits Enter, the input is returned as a string.

Basic Usage

Here’s how to use the input() function:

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

• In this example, the program prompts the user to enter their name and then greets them with a message.

Converting Input Types

Since input() returns data as a string, you may need to convert it to another data type (like int, float, etc.) for mathematical operations. You can do this using type conversion functions.

age = input("Enter your age: ")
age = int(age)  # Convert the input string to an integer
print("In ten years, you will be", age + 10)

• Here, the program asks for the user's age, converts it from a string to an integer, and then calculates and displays their age in ten years.

Example of Multiple Inputs

You can take multiple inputs in a single line using the split() method to separate values based on spaces or other delimiters.

# Taking multiple inputs
data = input("Enter your name and age (separated by space): ")
name, age = data.split()  # Split the input into two variables
age = int(age)  # Convert age to integer
print(f"{name} is {age} years old.")

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2. Displaying Output with print()

The print() function is used to display output to the console. You can print strings, numbers, and the results of expressions.

Basic Usage

print("Hello, World!")

• This will display Hello, World! in the console.

Printing Variables

You can print the value of variables directly:

name = "Alice"
age = 25
print(name)
print(age)

Formatting Output

There are several ways to format the output in Python:

1. Using Commas: You can separate multiple items in the print() function with commas.

print("Name:", name, "Age:", age)

2. String Concatenation: Combine strings and variables using the + operator. Make sure to convert non-string values to strings first.

print("Name: " + name + ", Age: " + str(age))

3. Formatted Strings (f-strings): Introduced in Python 3.6, f-strings allow you to embed expressions inside string literals.

print(f"{name} is {age} years old.")

4. str.format() Method: You can also use the str.format() method for formatting.

print("{} is {} years old.".format(name, age))

5. Old-style Formatting: Use % for string formatting (less common now).

print("%s is %d years old." % (name, age))

Printing on the Same Line

By default, print() adds a newline at the end. To print on the same line, use the end parameter:

print("Hello", end=", ")
print("World!")  # Output: Hello, World!

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3. Example Program

Here’s a simple example that combines input and output:

# Get user input
name = input("Enter your name: ")
age = input("Enter your age: ")
age = int(age)  # Convert age to integer

# Display formatted output
print(f"Hello, {name}! You are {age} years old.")
print(f"In 5 years, you will be {age + 5} years old.")

Summary

Taking input and displaying output in Python is straightforward and flexible. The input() function allows you to gather user data, while the print() function provides various ways to output information to the console. Understanding how to effectively use these functions will enhance your ability to create interactive Python programs.