twisted :: python :: filepath :: FilePath :: Class FilePath

Class FilePath

      object --+    
               |    
AbstractFilePath --+
                   |
                  FilePath

Known Subclasses:

web.static.File

I am a path on the filesystem that only permits 'downwards' access.

Instantiate me with a pathname (for example, FilePath('/home/myuser/public_html')) and I will attempt to only provide access to files which reside inside that path. I may be a path to a file, a directory, or a file which does not exist.

The correct way to use me is to instantiate me, and then do ALL filesystem access through me. In other words, do not import the 'os' module; if you need to open a file, call my 'open' method. If you need to list a directory, call my 'path' method.

Even if you pass me a relative path, I will convert that to an absolute path internally.

Note: although time-related methods do return floating-point results, they may still be only second resolution depending on the platform and the last value passed to os.stat_float_times. If you want greater-than-second precision, call os.stat_float_times(True), or use Python 2.5. Greater-than-second precision is only available in Windows on Python2.5 and later.

Nested Classes
	clonePath I am a path on the filesystem that only permits 'downwards' access.

Instance Methods

__init__(self, path, alwaysCreate=False)
Convert a path string to an absolute path if necessary and initialize the FilePath with the result.

__getstate__(self)
Support serialization by discarding cached os.stat results and returning everything else.

child(self, path)
Create and return a new FilePath representing a path contained by self.

preauthChild(self, path)
Use me if `path' might have slashes in it, but you know they're safe.

childSearchPreauth(self, *paths)
Return my first existing child with a name in 'paths'.

siblingExtensionSearch(self, *exts)
Attempt to return a path with my name, given multiple possible extensions.

realpath(self)
Returns the absolute target as a FilePath if self is a link, self otherwise.

siblingExtension(self, ext)

linkTo(self, linkFilePath)
Creates a symlink to self to at the path in the FilePath linkFilePath.

file

open(self, mode='r')
Open this file using mode or for writing if alwaysCreate is True.

restat(self, reraise=True)
Re-calculate cached effects of 'stat'.

changed(self)
Clear any cached information about the state of this path on disk.

chmod(self, mode)
Changes the permissions on self, if possible.

getsize(self)

float

getModificationTime(self)
Retrieve the time of last access from this file.

float

getStatusChangeTime(self)
Retrieve the time of the last status change for this file.

float

getAccessTime(self)
Retrieve the time that this file was last accessed.

long

getInodeNumber(self)
Retrieve the file serial number, also called inode number, which distinguishes this file from all other files on the same device.

long

getDevice(self)
Retrieves the device containing the file.

int

getNumberOfHardLinks(self)
Retrieves the number of hard links to the file.

int

getUserID(self)
Returns the user ID of the file's owner.

int

getGroupID(self)
Returns the group ID of the file.

Permissions

getPermissions(self)
Returns the permissions of the file.

bool

exists(self)
Check if this FilePath exists.

isdir(self)
Returns: True if this FilePath refers to a directory, False otherwise.

isfile(self)
Returns: True if this FilePath points to a regular file (not a directory, socket, named pipe, etc), False otherwise.

bool

isBlockDevice(self)
Returns whether the underlying path is a block device.

bool

isSocket(self)
Returns whether the underlying path is a socket.

islink(self)
Returns: True if this FilePath points to a symbolic link.

isabs(self)
Returns: True, always.

listdir(self)
List the base names of the direct children of this FilePath.

splitext(self)
Returns: tuple where the first item is the filename and second item is the file extension.

__repr__(self)
repr(x)

touch(self)
Updates the access and last modification times of the file at this file path to the current time.

remove(self)
Removes the file or directory that is represented by self.

makedirs(self)
Create all directories not yet existing in path segments, using os.makedirs.

globChildren(self, pattern)
Assuming I am representing a directory, return a list of FilePaths representing my children that match the given pattern.

str

basename(self)
Returns: The final component of the FilePath's path (Everything after the final path separator).

str

dirname(self)
Returns: All of the components of the FilePath's path except the last one (everything up to the final path separator).

parent(self)
Returns: A FilePath representing the path which directly contains this FilePath.

setContent(self, content, ext='.new')
Replace the file at this path with a new file that contains the given bytes, trying to avoid data-loss in the meanwhile.

__cmp__(self, other)

createDirectory(self)
Create the directory the FilePath refers to.

requireCreate(self, val=1)

create(self)
Exclusively create a file, only if this file previously did not exist.

FilePath

temporarySibling(self, extension='')
Construct a path referring to a sibling of this path.

copyTo(self, destination, followLinks=True)
Copies self to destination.

moveTo(self, destination, followLinks=True)
Move self to destination - basically renaming self to whatever destination is named.

__provides__(...)
Special descriptor for class __provides__

Inherited from AbstractFilePath: __hash__, __providedBy__, children, descendant, getContent, getatime, getctime, getmtime, parents, segmentsFrom, sibling, walk

Inherited from object: __delattr__, __format__, __getattribute__, __new__, __reduce__, __reduce_ex__, __setattr__, __sizeof__, __str__, __subclasshook__

Class Variables
	sep = `'/'`
	__implemented__ = `<implementedBy twisted.python.filepath.FileP...`

Instance Variables
`int` or `types.NoneType` or `os.stat_result`	statinfo = `None` The currently cached status information about the file on the filesystem that this `FilePath` points to.
`str`	path = `None` The path from which 'downward' traversal is permitted.
`bool`	alwaysCreate When opening this file, only succeed if the file does not already exist.

Properties
Inherited from `object`: `__class__`

Method Details

init(self, path, alwaysCreate=False)
(Constructor)

Convert a path string to an absolute path if necessary and initialize the FilePath with the result.

Overrides: object.__init__

child(self, path)

Create and return a new FilePath representing a path contained by self.

Parameters:

path (str) - The base name of the new FilePath. If this contains directory separators or parent references it will be rejected.

Raises:

InsecurePath - If the result of combining this path with path would result in a path which is not a direct child of this path.

preauthChild(self, path)

Use me if `path' might have slashes in it, but you know they're safe.

(NOT slashes at the beginning. It still needs to be a _child_).

childSearchPreauth(self, *paths)

Return my first existing child with a name in 'paths'.

paths is expected to be a list of *pre-secured* path fragments; in most cases this will be specified by a system administrator and not an arbitrary user.

If no appropriately-named children exist, this will return None.

siblingExtensionSearch(self, *exts)

Attempt to return a path with my name, given multiple possible extensions.

Each extension in exts will be tested and the first path which exists will be returned. If no path exists, None will be returned. If '' is in exts, then if the file referred to by this path exists, 'self' will be returned.

The extension '*' has a magic meaning, which means "any path that begins with self.path+'.' is acceptable".

realpath(self)

Returns the absolute target as a FilePath if self is a link, self otherwise. The absolute link is the ultimate file or directory the link refers to (for instance, if the link refers to another link, and another...). If the filesystem does not support symlinks, or if the link is cyclical, raises a LinkError.

Behaves like os.path.realpath in that it does not resolve link names in the middle (ex. /x/y/z, y is a link to w - realpath on z will return /x/y/z, not /x/w/z).

Returns:

FilePath of the target path

Raises:

LinkError - if links are not supported or links are cyclical.

linkTo(self, linkFilePath)

Creates a symlink to self to at the path in the FilePath linkFilePath. Only works on posix systems due to its dependence on os.symlink. Propagates OSErrors up from os.symlink if linkFilePath.parent() does not exist, or linkFilePath already exists.

Parameters:

linkFilePath (FilePath) - a FilePath representing the link to be created

open(self, mode=`'r'`)

Open this file using mode or for writing if alwaysCreate is True.

In all cases the file is opened in binary mode, so it is not necessary to include b in mode.

Parameters:

mode (str) - The mode to open the file in. Default is r.

Returns: file

An open file object.

Raises:

AssertionError - If a is included in the mode and alwaysCreate is True.

restat(self, reraise=True)

Re-calculate cached effects of 'stat'. To refresh information on this path after you know the filesystem may have changed, call this method.

Parameters:

reraise - a boolean. If true, re-raise exceptions from os.stat; otherwise, mark this path as not existing, and remove any cached stat information.

Raises:

Exception - is reraise is True and an exception occurs while reloading metadata.

changed(self)

Clear any cached information about the state of this path on disk.

Since: 10.1.0

chmod(self, mode)

Changes the permissions on self, if possible. Propagates errors from os.chmod up.

Parameters:

mode (int) - integer representing the new permissions desired (same as the command line chmod)

getModificationTime(self)

Retrieve the time of last access from this file.

Returns: float: a number of seconds from the epoch.

getStatusChangeTime(self)

Retrieve the time of the last status change for this file.

Returns: float: a number of seconds from the epoch.

getAccessTime(self)

Retrieve the time that this file was last accessed.

Returns: float: a number of seconds from the epoch.

getInodeNumber(self)

Retrieve the file serial number, also called inode number, which distinguishes this file from all other files on the same device.

Returns: long: a number representing the file serial number

Since: 11.0

getDevice(self)

Retrieves the device containing the file. The inode number and device number together uniquely identify the file, but the device number is not necessarily consistent across reboots or system crashes.

Returns: long: a number representing the device

Since: 11.0

getNumberOfHardLinks(self)

Retrieves the number of hard links to the file. This count keeps track of how many directories have entries for this file. If the count is ever decremented to zero then the file itself is discarded as soon as no process still holds it open. Symbolic links are not counted in the total.

Returns: int: the number of hard links to the file

Since: 11.0

getUserID(self)

Returns the user ID of the file's owner.

Returns: int: the user ID of the file's owner

Since: 11.0

getGroupID(self)

Returns the group ID of the file.

Returns: int: the group ID of the file

Since: 11.0

getPermissions(self)

Returns the permissions of the file. Should also work on Windows, however, those permissions may not what is expected in Windows.

Returns: Permissions: the permissions for the file

Since: 11.1

exists(self)

Check if this FilePath exists.

Returns: bool: True if the stats of path can be retrieved successfully, False in the other cases.

isdir(self)

Returns:: True if this FilePath refers to a directory, False otherwise.

isfile(self)

Returns:: True if this FilePath points to a regular file (not a directory, socket, named pipe, etc), False otherwise.

isBlockDevice(self)

Returns whether the underlying path is a block device.

Returns: bool: True if it is a block device, False otherwise

Since: 11.1

isSocket(self)

Returns whether the underlying path is a socket.

Returns: bool: True if it is a socket, False otherwise

Since: 11.1

islink(self)

Returns:: True if this FilePath points to a symbolic link.

isabs(self)

Returns:: True, always.

listdir(self)

List the base names of the direct children of this FilePath.

Returns:: a list of str giving the names of the contents of the directory this FilePath refers to. These names are relative to this FilePath.

splitext(self)

Returns:: tuple where the first item is the filename and second item is the file extension. See Python docs for os.path.splitext

repr(self)
(Representation operator)

repr(x)

Overrides: object.__repr__: (inherited documentation)

touch(self)

Updates the access and last modification times of the file at this file path to the current time. Also creates the file if it does not already exist.

Raises:

Exception - if unable to create or modify the last modification time of the file.

remove(self)

Removes the file or directory that is represented by self. If self.path is a directory, recursively remove all its children before removing the directory. If it's a file or link, just delete it.

basename(self)

Returns: str: The final component of the FilePath's path (Everything after the final path separator).

dirname(self)

Returns: str: All of the components of the FilePath's path except the last one (everything up to the final path separator).

parent(self)

Returns:: A FilePath representing the path which directly contains this FilePath.

setContent(self, content, ext=`'.new'`)

Replace the file at this path with a new file that contains the given bytes, trying to avoid data-loss in the meanwhile.

On UNIX-like platforms, this method does its best to ensure that by the time this method returns, either the old contents or the new contents of the file will be present at this path for subsequent readers regardless of premature device removal, program crash, or power loss, making the following assumptions:

your filesystem is journaled (i.e. your filesystem will not itself lose data due to power loss)
your filesystem's rename() is atomic
your filesystem will not discard new data while preserving new metadata (see http://mjg59.livejournal.com/108257.html for more detail)

On most versions of Windows there is no atomic rename() (see http://bit.ly/win32-overwrite for more information), so this method is slightly less helpful. There is a small window where the file at this path may be deleted before the new file is moved to replace it: however, the new file will be fully written and flushed beforehand so in the unlikely event that there is a crash at that point, it should be possible for the user to manually recover the new version of their data. In the future, Twisted will support atomic file moves on those versions of Windows which do support them: see Twisted ticket 3004.

This method should be safe for use by multiple concurrent processes, but note that it is not easy to predict which process's contents will ultimately end up on disk if they invoke this method at close to the same time.

Parameters:

content (str) - The desired contents of the file at this path.
ext (str) - An extension to append to the temporary filename used to store the bytes while they are being written. This can be used to make sure that temporary files can be identified by their suffix, for cleanup in case of crashes.

createDirectory(self)

Create the directory the FilePath refers to.

Raises:

OSError - If the directory cannot be created.

See Also: makedirs

temporarySibling(self, extension=`''`)

Construct a path referring to a sibling of this path.

The resulting path will be unpredictable, so that other subprocesses should neither accidentally attempt to refer to the same path before it is created, nor they should other processes be able to guess its name in advance.

Parameters:

extension (str) - A suffix to append to the created filename. (Note that if you want an extension with a '.' you must include the '.' yourself.)

Returns: FilePath

a path object with the given extension suffix, alwaysCreate set to True.

copyTo(self, destination, followLinks=True)

Copies self to destination.

If self doesn't exist, an OSError is raised.

If self is a directory, this method copies its children (but not itself) recursively to destination - if destination does not exist as a directory, this method creates it. If destination is a file, an IOError will be raised.

If self is a file, this method copies it to destination. If destination is a file, this method overwrites it. If destination is a directory, an IOError will be raised.

If self is a link (and followLinks is False), self will be copied over as a new symlink with the same target as returned by os.readlink. That means that if it is absolute, both the old and new symlink will link to the same thing. If it's relative, then perhaps not (and it's also possible that this relative link will be broken).

File/directory permissions and ownership will NOT be copied over.

If followLinks is True, symlinks are followed so that they're treated as their targets. In other words, if self is a link, the link's target will be copied. If destination is a link, self will be copied to the destination's target (the actual destination will be destination's target). Symlinks under self (if self is a directory) will be followed and its target's children be copied recursively.

If followLinks is False, symlinks will be copied over as symlinks.

Parameters:

destination - the destination (a FilePath) to which self should be copied
followLinks - whether symlinks in self should be treated as links or as their targets

moveTo(self, destination, followLinks=True)

Move self to destination - basically renaming self to whatever destination is named. If destination is an already-existing directory, moves all children to destination if destination is empty. If destination is a non-empty directory, or destination is a file, an OSError will be raised.

If moving between filesystems, self needs to be copied, and everything that applies to copyTo applies to moveTo.

Parameters:

destination - the destination (a FilePath) to which self should be copied
followLinks - whether symlinks in self should be treated as links or as their targets (only applicable when moving between filesystems)

provides(...)

Special descriptor for class __provides__

The descriptor caches the implementedBy info, so that we can get declarations for objects without instance-specific interfaces a bit quicker.

Overrides: AbstractFilePath.__provides__

Class Variable Details

implemented

Value:

<implementedBy twisted.python.filepath.FilePath>

Instance Variable Details

statinfo

The currently cached status information about the file on the filesystem that this FilePath points to. This attribute is None if the file is in an indeterminate state (either this FilePath has not yet had cause to call stat() yet or FilePath.changed indicated that new information is required), 0 if stat() was called and returned an error (i.e. the path did not exist when stat() was called), or a stat_result object that describes the last known status of the underlying file (or directory, as the case may be). Trust me when I tell you that you do not want to use this attribute. Instead, use the methods on FilePath which give you information about it, like getsize(), isdir(), getModificationTime(), and so on.

Type:: int or types.NoneType or os.stat_result

Value:

None

Class FilePath

__init__(self, path, alwaysCreate=False) (Constructor)

child(self, path)

preauthChild(self, path)

childSearchPreauth(self, *paths)

siblingExtensionSearch(self, *exts)

realpath(self)

linkTo(self, linkFilePath)

open(self, mode='r')

restat(self, reraise=True)

changed(self)

chmod(self, mode)

getModificationTime(self)

getStatusChangeTime(self)

getAccessTime(self)

getInodeNumber(self)

getDevice(self)

getNumberOfHardLinks(self)

getUserID(self)

getGroupID(self)

getPermissions(self)

exists(self)

isdir(self)

isfile(self)

isBlockDevice(self)

isSocket(self)

islink(self)

isabs(self)

listdir(self)

splitext(self)

__repr__(self) (Representation operator)

touch(self)

remove(self)

basename(self)

dirname(self)

parent(self)

setContent(self, content, ext='.new')

createDirectory(self)

temporarySibling(self, extension='')

copyTo(self, destination, followLinks=True)

moveTo(self, destination, followLinks=True)

__provides__(...)

__implemented__

statinfo

init(self, path, alwaysCreate=False)
(Constructor)

open(self, mode=`'r'`)

repr(self)
(Representation operator)

setContent(self, content, ext=`'.new'`)

temporarySibling(self, extension=`''`)

provides(...)

implemented