Python to Implementation of Cat Command For Beginners

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Cat command implementation using python.

Run:

On Linux, you can use 

./cat.py [path]

OR

python ./cat.py [path]

Example:

./cat.py ./test_cat.txt

Source Code:

cat.py

#!/usr/bin/python

import argparse
from pathlib import Path
from sys import stderr, stdout
import os

class CatError(Exception):
    pass

class Logger:
    def __init__(self, verbosity=False):
        self.verbose = verbosity

    def error(self, message):
        print(f'ERROR: {message}')

logger = Logger()

'''
    Read the selected text file 
    Example:
    your/path/file.txt
'''
def readFile(src: Path):

    '''
        if the given path is a directory
        ERROR the path is a directory
    '''
    if src.is_dir():

        logger.error(f'The path {src}: is a directory')

    else:

        with open(src, 'r') as f:
            for lines in f:
                print(lines, end='')

def cli() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        prog='cat',
        description='cat command implementation in python',
        epilog='Example: your/path/file.txt'
    )

    parser.add_argument(
        'source',
        type=Path,
        help='Source file'
    )

    return parser.parse_args()

def main():

    args = cli()

    try:

        readFile(args.source)

    except CatError as e:

        logger.error(e)

        exit(1)

    except KeyboardInterrupt:

        logger.error('\nInterrupt')

'''
    Start the program
'''
if __name__ == '__main__':
    main()

test_cat.txt

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam consequat elit vel pretium pellentesque. Vivamus commodo leo sed lorem auctor elementum. Maecenas ut erat ut velit maximus luctus. Vestibulum varius justo et mauris tristique pharetra rutrum porta nulla. Nam porttitor lobortis posuere. Aenean erat nisl, aliquam id molestie in, luctus quis mauris. Donec fermentum vel quam in consectetur. Aliquam nec mauris quis tellus faucibus fermentum. Suspendisse ac maximus sem. Fusce feugiat non dui non gravida. Ut ac eleifend tellus. Vivamus consectetur finibus nisi. Etiam id odio vitae arcu aliquam tincidunt nec sit amet quam.

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