t.p.f.FilePath(_PathHelper) : class documentation

Part of twisted.python.filepath View Source View In Hierarchy

Known subclasses: twisted.web.static.File, twisted.web.twcgi.CGIDirectory

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.

Instance Variables	alwaysCreate	When opening this file, only succeed if the file does not already exist. (type: `bool` )
	path	The path from which 'downward' traversal is permitted. (type: `str` )
	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` )

Method	__init__	Undocumented
Method	__getstate__	Undocumented
Method	child	Undocumented
Method	preauthChild	Use me if `path' might have slashes in it, but you know they're safe.
Method	childSearchPreauth	Return my first existing child with a name in 'paths'.
Method	siblingExtensionSearch	Attempt to return a path with my name, given multiple possible extensions.
Method	realpath	No summary
Method	siblingExtension	Undocumented
Method	linkTo	No summary
Method	open	Open this file using `mode` or for writing if `alwaysCreate` is `True`.
Method	restat	Re-calculate cached effects of 'stat'. To refresh information on this path after you know the filesystem may have changed, call this method.
Method	changed	Clear any cached information about the state of this path on disk.
Method	chmod	Changes the permissions on self, if possible. Propagates errors from `os.chmod` up.
Method	getsize	Undocumented
Method	getModificationTime	Retrieve the time of last access from this file.
Method	getStatusChangeTime	Retrieve the time of the last status change for this file.
Method	getAccessTime	Retrieve the time that this file was last accessed.
Method	getInodeNumber	Retrieve the file serial number, also called inode number, which distinguishes this file from all other files on the same device.
Method	getDevice	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.
Method	getNumberOfHardLinks	No summary
Method	getUserID	Returns the user ID of the file's owner.
Method	getGroupID	Returns the group ID of the file.
Method	exists	Check if the `path` exists.
Method	isdir	Undocumented
Method	isfile	Undocumented
Method	islink	Undocumented
Method	isabs	Undocumented
Method	listdir	Undocumented
Method	splitext	Undocumented
Method	__repr__	Undocumented
Method	touch	Undocumented
Method	remove	No summary
Method	makedirs	Create all directories not yet existing in `path` segments, using `os.makedirs`.
Method	globChildren	Assuming I am representing a directory, return a list of FilePaths representing my children that match the given pattern.
Method	basename	Undocumented
Method	dirname	Undocumented
Method	parent	Undocumented
Method	setContent	Replace the file at this path with a new file that contains the given bytes, trying to avoid data-loss in the meanwhile.
Method	__cmp__	Undocumented
Method	createDirectory	Undocumented
Method	requireCreate	Undocumented
Method	create	Exclusively create a file, only if this file previously did not exist.
Method	temporarySibling	Construct a path referring to a sibling of this path.
Method	copyTo	Copies self to destination.
Method	moveTo	No summary

Inherited from _PathHelper:

Method	getContent	Undocumented
Method	parents
Method	children	List the children of this path object.
Method	walk	No summary
Method	sibling	Undocumented
Method	descendant	Retrieve a child or child's child of this path.
Method	segmentsFrom	Return a list of segments between a child and its ancestor.
Method	__hash__	Hash the same as another FilePath with the same path as mine.
Method	getmtime	Deprecated. Use getModificationTime instead.
Method	getatime	Deprecated. Use getAccessTime instead.
Method	getctime	Deprecated. Use getStatusChangeTime instead.

def __init__(self, path, alwaysCreate=False): (source)

overridden in twisted.web.static.File, twisted.web.twcgi.CGIDirectory

Undocumented

def __getstate__(self): (source)

Undocumented

def child(self, path): (source)

Undocumented

def preauthChild(self, path): (source)

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_).

def childSearchPreauth(self, *paths): (source)

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.

def siblingExtensionSearch(self, *exts): (source)

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".

def realpath(self): (source)

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.

def siblingExtension(self, ext): (source)

Undocumented

def linkTo(self, linkFilePath): (source)

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 a FilePath representing the link to be created (type: FilePath )

def open(self, mode='r'): (source)

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	The mode to open the file in. Default is `r`. (type: `str` )
Returns	An open `file` object. (type: `file` )
Raises	AssertionError	If `a` is included in the mode and `alwaysCreate` is `True`.

def restat(self, reraise=True): (source)

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.

def changed(self): (source)

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

Present Since 10.1.0

def chmod(self, mode): (source)

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

Parameters mode integer representing the new permissions desired (same as the command line chmod) (type: int )

def getsize(self): (source)

Undocumented

def getModificationTime(self): (source)

Retrieve the time of last access from this file.

Returns a number of seconds from the epoch. (type: float )

def getStatusChangeTime(self): (source)

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

Returns a number of seconds from the epoch. (type: float )

def getAccessTime(self): (source)

Retrieve the time that this file was last accessed.

Returns a number of seconds from the epoch. (type: float )

def getInodeNumber(self): (source)

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

Returns	a number representing the file serial number (type: `long` )
Raises	NotImplementedError if the platform is Windows, since the inode number would be a dummy value for all files in Windows
Present Since	11.0

def getDevice(self): (source)

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	a number representing the device (type: `long` )
Raises	NotImplementedError if the platform is Windows, since the device number would be 0 for all partitions on a Windows platform
Present Since	11.0

def getNumberOfHardLinks(self): (source)

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	the number of hard links to the file (type: `int` )
Raises	NotImplementedError if the platform is Windows, since Windows doesn't maintain a link count for directories, and os.stat does not set st_nlink on Windows anyway.
Present Since	11.0

def getUserID(self): (source)

Returns the user ID of the file's owner.

Returns	the user ID of the file's owner (type: `int` )
Raises	NotImplementedError if the platform is Windows, since the UID is always 0 on Windows
Present Since	11.0

def getGroupID(self): (source)

Returns the group ID of the file.

Returns	the group ID of the file (type: `int` )
Raises	NotImplementedError if the platform is Windows, since the GID is always 0 on windows
Present Since	11.0

def exists(self): (source)

Check if the path exists.

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

def isdir(self): (source)

Undocumented

def isfile(self): (source)

Undocumented

def islink(self): (source)

Undocumented

def isabs(self): (source)

Undocumented

def listdir(self): (source)

Undocumented

def splitext(self): (source)

Undocumented

def __repr__(self): (source)

Undocumented

def touch(self): (source)

Undocumented

def remove(self): (source)

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.

def makedirs(self): (source)

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

def globChildren(self, pattern): (source)

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

def basename(self): (source)

Undocumented

def dirname(self): (source)

Undocumented

def parent(self): (source)

Undocumented

def setContent(self, content, ext='.new'): (source)

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	The desired contents of the file at this path. (type: `str` )
	ext	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. (type: `str` )

def __cmp__(self, other): (source)

Undocumented

def createDirectory(self): (source)

Undocumented

def requireCreate(self, val=1): (source)

Undocumented

def create(self): (source)

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

def temporarySibling(self, extension=''): (source)

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	A suffix to append to the created filename. (Note that if you want an extension with a '.' you must include the '.' yourself.) (type: `str` )
Returns	a path object with the given extension suffix, `alwaysCreate` set to True. (type: `FilePath` )

def copyTo(self, destination, followLinks=True): (source)

Copies self to destination.

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

def moveTo(self, destination, followLinks=True): (source)

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)

API Documentation for Twisted, generated by pydoctor at 2011-10-27 16:27:37.