Mount Filesystem¶
A Mount FS is a virtual filesystem which can seamlessly map sub-directories on to other filesystems.
For example, lets say we have two filesystems containing config files and resources respectively:
[config_fs]
|-- config.cfg
`-- defaults.cfg
[resources_fs]
|-- images
| |-- logo.jpg
| `-- photo.jpg
`-- data.dat
We can combine these filesystems in to a single filesystem with the following code:
from fs.mountfs import MountFS
combined_fs = MountFS()
combined_fs.mount('config', config_fs)
combined_fs.mount('resources', resources_fs)
This will create a filesystem where paths under config/
map to
config_fs
, and paths under resources/
map to resources_fs
:
[combined_fs]
|-- config
| |-- config.cfg
| `-- defaults.cfg
`-- resources
|-- images
| |-- logo.jpg
| `-- photo.jpg
`-- data.dat
Now both filesystems may be accessed with the same path structure:
print(combined_fs.gettext('/config/defaults.cfg'))
read_jpg(combined_fs.open('/resources/images/logo.jpg', 'rb')
-
class
fs.mountfs.
MountFS
(auto_close=True)[source]¶ A virtual filesystem that maps directories on to other file-systems.
-
__init__
(auto_close=True)[source]¶ Create a new
MountFS
instance.Parameters: auto_close (bool) – If True
(the default), the child filesystems will be closed whenMountFS
is closed.
-
close
()[source]¶ Close the filesystem and release any resources.
It is important to call this method when you have finished working with the filesystem. Some filesystems may not finalize changes until they are closed (archives for example). You may call this method explicitly (it is safe to call close multiple times), or you can use the filesystem as a context manager to automatically close.
Example
>>> with OSFS('~/Desktop') as desktop_fs: ... desktop_fs.writetext( ... 'note.txt', ... "Don't forget to tape Game of Thrones" ... )
If you attempt to use a filesystem that has been closed, a
FilesystemClosed
exception will be thrown.
-
desc
(path)[source]¶ Return a short descriptive text regarding a path.
Parameters: path (str) – A path to a resource on the filesystem. Returns: a short description of the path. Return type: str Raises: fs.errors.ResourceNotFound
– Ifpath
does not exist.
-
download
(path, file, chunk_size=None, **options)[source]¶ Copy a file from the filesystem to a file-like object.
This may be more efficient that opening and copying files manually if the filesystem supplies an optimized method.
Note that the file object
file
will not be closed by this method. Take care to close it after this method completes (ideally with a context manager).Parameters: - path (str) – Path to a resource.
- file (file-like) – A file-like object open for writing in binary mode.
- chunk_size (int, optional) – Number of bytes to read at a
time, if a simple copy is used, or
None
to use sensible default. - **options – Implementation specific options required to open the source file.
Example
>>> with open('starwars.mov', 'wb') as write_file: ... my_fs.download('/Videos/starwars.mov', write_file)
Raises: fs.errors.ResourceNotFound
– ifpath
does not exist.
-
getinfo
(path, namespaces=None)[source]¶ Get information about a resource on a filesystem.
Parameters: Returns: resource information object.
Return type: Raises: fs.errors.ResourceNotFound
– Ifpath
does not exist.For more information regarding resource information, see Resource Info.
-
getsize
(path)[source]¶ Get the size (in bytes) of a resource.
Parameters: path (str) – A path to a resource. Returns: the size of the resource. Return type: int Raises: fs.errors.ResourceNotFound
– ifpath
does not exist.The size of a file is the total number of readable bytes, which may not reflect the exact number of bytes of reserved disk space (or other storage medium).
The size of a directory is the number of bytes of overhead use to store the directory entry.
-
getsyspath
(path)[source]¶ Get the system path of a resource.
Parameters: path (str) – A path on the filesystem. Returns: the system path of the resource, if any. Return type: str Raises: fs.errors.NoSysPath
– If there is no corresponding system path.A system path is one recognized by the OS, that may be used outside of PyFilesystem (in an application or a shell for example). This method will get the corresponding system path that would be referenced by
path
.Not all filesystems have associated system paths. Network and memory based filesystems, for example, may not physically store data anywhere the OS knows about. It is also possible for some paths to have a system path, whereas others don’t.
This method will always return a str on Py3.* and unicode on Py2.7. See
getospath
if you need to encode the path as bytes.If
path
doesn’t have a system path, aNoSysPath
exception will be thrown.Note
A filesystem may return a system path even if no resource is referenced by that path – as long as it can be certain what that system path would be.
-
gettype
(path)[source]¶ Get the type of a resource.
Parameters: path (str) – A path on the filesystem. Returns: the type of the resource. Return type: ResourceType Raises: fs.errors.ResourceNotFound
– ifpath
does not exist.A type of a resource is an integer that identifies the what the resource references. The standard type integers may be one of the values in the
ResourceType
enumerations.The most common resource types, supported by virtually all filesystems are
directory
(1) andfile
(2), but the following types are also possible:ResourceType value unknown 0 directory 1 file 2 character 3 block_special_file 4 fifo 5 socket 6 symlink 7 Standard resource types are positive integers, negative values are reserved for implementation specific resource types.
-
geturl
(path, purpose='download')[source]¶ Get the URL to a given resource.
Parameters: - path (str) – A path on the filesystem
- purpose (str) – A short string that indicates which URL
to retrieve for the given path (if there is more than
one). The default is
'download'
, which should return a URL that serves the file. Other filesystems may support other values forpurpose
: for instance,OSFS
supports'fs'
, which returns a FS URL (see FS URLs).
Returns: a URL.
Return type: Raises: fs.errors.NoURL
– If the path does not map to a URL.
-
hasurl
(path, purpose='download')[source]¶ Check if a path has a corresponding URL.
Parameters: Returns: True
if an URL for the given purpose exists.Return type:
-
isdir
(path)[source]¶ Check if a path maps to an existing directory.
Parameters: path (str) – A path on the filesystem. Returns: True
ifpath
maps to a directory.Return type: bool
-
isfile
(path)[source]¶ Check if a path maps to an existing file.
Parameters: path (str) – A path on the filesystem. Returns: True
ifpath
maps to a file.Return type: bool
-
listdir
(path)[source]¶ Get a list of the resource names in a directory.
This method will return a list of the resources in a directory. A resource is a file, directory, or one of the other types defined in
ResourceType
.Parameters: path (str) – A path to a directory on the filesystem
Returns: list of names, relative to
path
.Return type: Raises: fs.errors.DirectoryExpected
– Ifpath
is not a directory.fs.errors.ResourceNotFound
– Ifpath
does not exist.
-
makedir
(path, permissions=None, recreate=False)[source]¶ Make a directory.
Parameters: Returns: a filesystem whose root is the new directory.
Return type: Raises: fs.errors.DirectoryExists
– If the path already exists.fs.errors.ResourceNotFound
– If the path is not found.
-
open
(path, mode='r', buffering=-1, encoding=None, errors=None, newline='', **options)[source]¶ Open a file.
Parameters: - path (str) – A path to a file on the filesystem.
- mode (str) – Mode to open the file object with (defaults to r).
- buffering (int) – Buffering policy (-1 to use default buffering, 0 to disable buffering, 1 to select line buffering, of any positive integer to indicate a buffer size).
- encoding (str) – Encoding for text files (defaults to
utf-8
) - errors (str, optional) – What to do with unicode decode errors
(see
codecs
module for more information). - newline (str) – Newline parameter.
- **options – keyword arguments for any additional information required by the filesystem (if any).
Returns: a file-like object.
Return type: Raises: fs.errors.FileExpected
– If the path is not a file.fs.errors.FileExists
– If the file exists, and exclusive mode is specified (x
in the mode).fs.errors.ResourceNotFound
– If the path does not exist.
-
openbin
(path, mode='r', buffering=-1, **kwargs)[source]¶ Open a binary file-like object.
Parameters: - path (str) – A path on the filesystem.
- mode (str) – Mode to open file (must be a valid non-text mode,
defaults to r). Since this method only opens binary files,
the
b
in the mode string is implied. - buffering (int) – Buffering policy (-1 to use default buffering, 0 to disable buffering, or any positive integer to indicate a buffer size).
- **options – keyword arguments for any additional information required by the filesystem (if any).
Returns: a file-like object.
Return type: Raises: fs.errors.FileExpected
– Ifpath
exists and is not a file.fs.errors.FileExists
– If thepath
exists, and exclusive mode is specified (x
in the mode).fs.errors.ResourceNotFound
– Ifpath
does not exist andmode
does not imply creating the file, or if any ancestor ofpath
does not exist.
-
readbytes
(path)[source]¶ Get the contents of a file as bytes.
Parameters: path (str) – A path to a readable file on the filesystem.
Returns: the file contents.
Return type: Raises: fs.errors.FileExpected
– ifpath
exists but is not a file.fs.errors.ResourceNotFound
– ifpath
does not exist.
-
readtext
(path, encoding=None, errors=None, newline='')[source]¶ Get the contents of a file as a string.
Parameters: Returns: file contents.
Return type: Raises: fs.errors.ResourceNotFound
– Ifpath
does not exist.
-
remove
(path)[source]¶ Remove a file from the filesystem.
Parameters: path (str) – Path of the file to remove.
Raises: fs.errors.FileExpected
– If the path is a directory.fs.errors.ResourceNotFound
– If the path does not exist.
-
removedir
(path)[source]¶ Remove a directory from the filesystem.
Parameters: path (str) – Path of the directory to remove.
Raises: fs.errors.DirectoryNotEmpty
– If the directory is not empty ( seeremovetree
for a way to remove the directory contents).fs.errors.DirectoryExpected
– If the path does not refer to a directory.fs.errors.ResourceNotFound
– If no resource exists at the given path.fs.errors.RemoveRootError
– If an attempt is made to remove the root directory (i.e.'/'
)
-
scandir
(path, namespaces=None, page=None)[source]¶ Get an iterator of resource info.
Parameters: - path (str) – A path to a directory on the filesystem.
- namespaces (list, optional) – A list of namespaces to include
in the resource information, e.g.
['basic', 'access']
. - page (tuple, optional) – May be a tuple of
(<start>, <end>)
indexes to return an iterator of a subset of the resource info, orNone
to iterate over the entire directory. Paging a directory scan may be necessary for very large directories.
Returns: an iterator of
Info
objects.Return type: Raises: fs.errors.DirectoryExpected
– Ifpath
is not a directory.fs.errors.ResourceNotFound
– Ifpath
does not exist.
-
setinfo
(path, info)[source]¶ Set info on a resource.
This method is the complement to
getinfo
and is used to set info values on a resource.Parameters: Raises: fs.errors.ResourceNotFound
– Ifpath
does not exist on the filesystemThe
info
dict should be in the same format as the raw info returned bygetinfo(file).raw
.Example
>>> details_info = {"details": { ... "modified": time.time() ... }} >>> my_fs.setinfo('file.txt', details_info)
-
upload
(path, file, chunk_size=None, **options)[source]¶ Set a file to the contents of a binary file object.
This method copies bytes from an open binary file to a file on the filesystem. If the destination exists, it will first be truncated.
Parameters: - path (str) – A path on the filesystem.
- file (io.IOBase) – a file object open for reading in binary mode.
- chunk_size (int, optional) – Number of bytes to read at a
time, if a simple copy is used, or
None
to use sensible default. - **options – Implementation specific options required to open the source file.
Raises: fs.errors.ResourceNotFound
– If a parent directory ofpath
does not exist.Note that the file object
file
will not be closed by this method. Take care to close it after this method completes (ideally with a context manager).Example
>>> with open('~/movies/starwars.mov', 'rb') as read_file: ... my_fs.upload('starwars.mov', read_file)
-
validatepath
(path)[source]¶ Validate a path, returning a normalized absolute path on sucess.
Many filesystems have restrictions on the format of paths they support. This method will check that
path
is valid on the underlaying storage mechanism and throw aInvalidPath
exception if it is not.Parameters: path (str) – A path.
Returns: A normalized, absolute path.
Return type: Raises: fs.errors.InvalidPath
– If the path is invalid.fs.errors.FilesystemClosed
– if the filesystem is closed.fs.errors.InvalidCharsInPath
– If the path contains invalid characters.
-
writebytes
(path, contents)[source]¶ Copy binary data to a file.
Parameters: Raises: TypeError
– if contents is not bytes.
-