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How to perform input and output operations in Python?

In Python, input and output (I/O) operations can be performed using various functions and methods. Here are some commonly used approaches for I/O operations:

1. Standard Input and Output (Console):
- `print()`: The `print()` function is used to display output on the console. It accepts one or more arguments and displays them as text.
- `input()`: The `input()` function is used to read input from the user via the console. It displays a prompt and waits for the user to enter a value, which is then returned as a string.

Example:

  # Output using print()
  print("Hello, World!")
  # Input using input()
  name = input("Enter your name: ")
  print("Hello,", name)

2. File Input and Output:
- Opening a file: To read from or write to a file, you need to open it using the `open()` function. It returns a file object that provides methods for reading from or writing to the file.
- Reading from a file: The `read()` method of the file object is used to read the entire contents of a file, while the `readline()` method reads a single line at a time.
- Writing to a file: The `write()` method of the file object is used to write text to a file. It can be called multiple times to write multiple lines or pieces of text.
- Closing a file: After performing file operations, it's important to close the file using the `close()` method to release system resources.

Example:

  # Opening a file for writing
  file = open("output.txt", "w")
  # Writing to the file
  file.write("Hello, World!\n")
  file.write("This is a sample file.")
  # Closing the file
  file.close()
  # Opening the file for reading
  file = open("output.txt", "r")
  # Reading from the file
  contents = file.read()
  print(contents)
  # Closing the file
  file.close()

3. Formatted Output (String Formatting):
- String formatting using `%`: You can use the `%` operator to format strings by substituting placeholders with values.
- String formatting using f-strings: Introduced in Python 3.6, f-strings (formatted string literals) provide a concise and expressive way to format strings by embedding expressions within curly braces ``.

Example:

  name = "Alice"
  age = 25
  # String formatting using %
  message = "My name is %s and I am %d years old." % (name, age)
  print(message)
  # String formatting using f-strings
  message = f"My name is {name} and I am {age} years old."
  print(message)
  

These are some of the commonly used methods for performing I/O operations in Python. You can choose the appropriate approach based on your specific requirements, whether it's displaying output on the console, reading user input, or performing file operations.

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