FileManager

import os
import shutil

__author__ = 'Evgeny Chernigovsky'


class Command:
    def __init__(self, function, arg_count):
        self.execute = function
        self.arg_count = arg_count


def create_directory(path):
    if os.path.exists(path):
        print('error: directory already exists')
        return

    os.makedirs(path)


def remove(path):
    if not os.path.exists(path):
        print('error: path not exists')
        return

    if os.path.isdir(path):
        shutil.rmtree(path)
    elif os.path.isfile(path):
        os.remove(path)
    else:
        print('error: path is not directory or file')


def move(source, destination):
    if not os.path.isfile(source) and not os.path.isdir(source):
        print('error: source is not directory or file')
        return

    if not os.path.isdir(destination):
        print('error: destination is not existing directory')
        return

    if os.path.commonprefix([os.path.abspath(source), os.path.abspath(destination)]) == os.path.abspath(source):
        print('error: source contains destination')
        return

    shutil.move(source, destination)


def copy(source, destination):
    if not os.path.isfile(source) and not os.path.isdir(source):
        print('error: source is not directory or file')
        return

    if not os.path.isdir(destination):
        print('error: destination is not existing directory')
        return

    if os.path.commonprefix([os.path.abspath(source), os.path.abspath(destination)]) == os.path.abspath(source):
        print('error: source contains destination')
        return

    shutil.copy(source, destination)


def program_exit():
    exit(0)


command_dict = {'createdir': Command(create_directory, 1),
                'remove': Command(remove, 1),
                'move': Command(move, 2),
                'copy': Command(copy, 2),
                'exit': Command(program_exit, 0)}


while True:
    print('$', end=' ')

    name, separator, args = input().strip().partition(' ')
    args = args.split()

    if not name in command_dict.keys():
        print('error: wrong command name')
        continue

    if len(args) != command_dict[name].arg_count:
        print('error: wrong argument count')
        continue

    command_dict[name].execute(*args)