filesystem.py

# 
# Your previous Plain Text content is preserved below:
# 
# Design a file system.
# File system only deals with directories
# Handle 3 basic commands.
# mkdir - create 1 or more directories (1 level only)
# ls - list files in current directory
# cd - change directory
# pwd - print working directory

class Directory():
    def __init__(self, name):
        self.contents = {}
        self.name = name
        
    def mkdir(self, *args):
        for arg in sorted(args):
            self.contents[arg] = Directory(arg)
            
    def get(self, name): return self.contents[name]
            
    def ls(self):
        return list(self.contents.keys())

class FileSystem():
    def __init__(self):
        self.root = Directory('')
        self.path = [self.root]
        
    def run(self, command):
        cmd, *args = command.split(' ')
        
        if cmd == 'mkdir': 
            self.loc().mkdir(*args)
        elif cmd == 'ls':
            return self.loc().ls()
        elif cmd == 'cd':
            return self.cd(args[0])
        elif cmd == 'pwd':
            return self.pwd()
            
    def pwd(self):
        return '/'.join([d.name for d in self.path])
            
    def loc(self): return self.path[-1]
            
    def cd(self, d):
        for p in d.split('/'): self._cd(p)
        
    def _cd(self, p):
        if p == '..': 
            self.path.pop()
        else:
            self.path.append(self.loc().get(p))
            
    def return_tree(self):
        queue = [self.root]
        tree = []
        while len(queue):
            item = queue.pop(0)
            for k in item.contents.values():
                tree.append(k.name)
                queue.append(k)
        return tree
        
        

# Part 1
fs = FileSystem()

fs.run('mkdir dir1 dir2')
assert fs.run('ls') == ['dir1', 'dir2']
print('MKDIR, LS - Success!')

fs.run('cd dir1')
fs.run('mkdir dir4 dir3')
assert fs.run('ls') == ['dir3', 'dir4']
print('CD - Success!')


fs.run('cd dir3')
assert fs.run('pwd') == '/dir1/dir3'
print('PWD - Success!')

# Part 2
fs.run('mkdir dir5 dir6')
fs.run('cd dir5')
fs.run('mkdir dir_last')
assert fs.run('ls') == ['dir_last']
assert fs.run('pwd') == '/dir1/dir3/dir5'
fs.run('cd ..')
assert fs.run('pwd') == '/dir1/dir3'
print('CD .. - Success!')

# Part 3
fs.run('cd ../../dir2')
fs.run('mkdir dir7 dir8')
assert fs.run('ls') == ['dir7', 'dir8']
print('CD ../.. - Success!')

# Part 4
assert fs.return_tree() == ['dir1', 'dir2', 'dir3', 'dir4', 'dir7', 'dir8', 'dir5', 'dir6', 'dir_last']
print('RETURN_TREE .. - Success!')