Python provides several ways to perform input and output operations.

Input in Python

There are several ways to read input from the user in Python.

input()

input() function reads a line of text from the user and returns it as a string.

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

raw_input()

raw_input() function (Python 2.x only) is similar to input(), but returns the input as a string without evaluating it as an expression.

sys.stdin

sys.stdin reads input from the standard input stream, which is usually the keyboard.

import sys

for line in sys.stdin:
print(line.strip())

Output in Python

There are several ways to display output to the user in Python:

print()

print() displays a message to the user, followed by a newline character.

print("Hello, World!")

sys.stdout

sys.stdout writes output to the standard output stream, which is usually the console.

import sys

sys.stdout.write("Hello, World!\n")

logging module

It provides a way to log messages at different levels (e.g., debug, info, warning, error).

import logging

logging.basicConfig(level=logging.INFO)
logging.info("Hello, World!")

Command-Line Interface

Here’s an example of a simple command-line interface that reads input from the user and writes output to the console.

def main():
    print("Welcome to My CLI!")
    while True:
        command = input("> ")
        if command == "quit":
            break
        elif command == "hello":
            print("Hello, World!")
        else:
            print("Invalid command. Try again!")

if __name__ == "__main__":
main()