print_dir_tree.py

import sys
import os


def print_dir_tree(dirname: str, indent: int=0):

    # Prints the indendations
    for i in range(indent):
        print("    ", end="")
        
    # Prints the file names
    print(os.path.basename(dirname))
    
    # Recurses on directories and their files
    if os.path.isdir(dirname):
    
        # Recurse for each file in a directory
        for files in os.listdir(dirname):
            print_dir_tree(os.path.join(dirname, files), indent+1)
            
            
if __name__ == "__main__":
    
    # Check argument supplied
    if len(sys.argv) - 1 != 1:
        raise SystemExit("Usage: <python print_dir_tree.py directory>")

    
    # Parse CMD Args
    the_dir = sys.argv[1]
    
    # Check directory exists
    if not os.path.exists(the_dir):
        raise SystemExit(f"The directory: {the_dir} does not exist.")
    
    # runs the program, passing in the name of the directory.
    print_dir_tree(the_dir)