I am trying to make something like FileSystem in python. My goal is to make files which can contain some data and Directories which can contain some files. Then I have some simple commands
cd
ls
mk_dir
mk_file
So, now I have a problem with this: There's DirectoryBase class which is different from Directory, because it has no ParentDir (Directory in that is File/Directory saved). Then there's Directory class that extends DirectoryBase and overwrites path() method (method returning path to file/dir) and data dict has another default key: '..', but when I am trying to find it in data dict it raises KeyError. Another weird thing, about it is that I am testing if file/dir exists, and if not it will return, so I don't know how this is possible, that it got KeyError.
This is my code:
class AttributeDictionary(dict):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.__getattr__ = self.__getitem__
self.__setattr__ = self.__setitem__
self.__delattr__ = self.__delitem__
class FileManager(object):
def __init__(self):
self.disk_dir = DirectoryBase('__disk__')
self.current_dir = self.disk_dir
def _find(self, path):
""" Gets file/dir object using path """
_cd = self.current_dir
for part in path:
_cd = _cd[part]
return _cd
def cmd_cd(self, path):
""" Classic unix `cd` command """
f = self._find(path)
if f is DirectoryBase:
self.current_dir = f
else:
return FileSystemError('DirectoryNotFound')
def cmd_ls(self):
""" Classic unix `ls` command """
return ConsoleOutput(''.join([f'{i}\n' for i in self.current_dir.data]))
def cmd_mkfile(self, name):
""" file making command """
self.current_dir.__setitem__(name, File(name, self.current_dir))
def cmd_mkdir(self, name):
""" file making command """
self.current_dir.__setitem__(name, Directory(name, self.current_dir))
class File(object):
def __init__(self, name, pd):
self.data = [0x00]
self.name = name
self.pd = pd
def path(self):
return [self.name] + self.pd.path()
def __sizeof__(self):
return len(self.data)
class DirectoryBase(AttributeDictionary):
def __init__(self, name, **kwargs):
super().__init__(**kwargs)
self.name = name
self.data = {'.': self}
def path(self):
return self.name
def __getitem__(self, item):
if item in self.data.keys():
return FileSystemError('FileNotFound')
return self.data[item] # KeyError: '..' found here
def __setitem__(self, key, value):
if key in self.data.keys():
return FileSystemError('FileAlreadyExists')
self.data[key] = value
def __delitem__(self, key):
if key in self.data.keys():
return FileSystemError('FileNotFound')
self.data.__delitem__(key)
class Directory(DirectoryBase):
def __init__(self, name, pd, **kwargs):
super().__init__(name, **kwargs)
self.pd = pd
self.data = {'.': self, '..': self.pd}
def path(self):
return [self.name] + self.pd.path()
if __name__ == '__main__':
fs = FileManager()
fs.cmd_mkdir('test')
print(fs.cmd_ls())
fs.cmd_cd(['test'])
fs.cmd_mkfile('idk.txt')
print(fs.cmd_ls())
fs.cmd_cd(['..'])
print(fs.cmd_ls())
Error looks like this:
.
test
Traceback (most recent call last):
.
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 106, in <module>
test
fs.cmd_cd(['..'])
idk.txt
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 32, in cmd_cd
f = self._find(path)
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 27, in _find
_cd = _cd[part]
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 76, in __getitem__
return self.data[item]
KeyError: '..'
or when I delete prints:
Traceback (most recent call last):
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 106, in <module>
fs.cmd_cd(['..'])
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 32, in cmd_cd
f = self._find(path)
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 27, in _find
_cd = _cd[part]
File "/Users/jan/PycharmProjects/Xaon/src/fs.py", line 76, in __getitem__
return self.data[item]
KeyError: '..'
Sorry if it is too confusing, I am beginner and my English is bad too.
the code logic is flawed:
def __getitem__(self, item):
if item in self.data.keys():
return FileSystemError('FileNotFound')
return self.data[item] # KeyError: '..' found here
you are throwing an error when the key exists. Just negate the condition (and drop the .keys() which is useless & unpythonic and even a performance killer in Python 2):
def __getitem__(self, item):
if item not in self.data:
return FileSystemError('FileNotFound')
return self.data[item]
there's the same error in __delitem__ BTW.
When fixed (and stubbed most of unexisting/unshown classes with str) I get the following output:
.
test
.
idk.txt
test
.
idk.txt
test