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

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

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

Implements interfaces: twisted.python.filepath.IFilePath

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.

On both Python 2 and Python 3, paths can only be bytes.

Instance Variable alwaysCreate When opening this file, only succeed if the file does not already exist. (type: bool)
Instance Variable path The path from which 'downward' traversal is permitted. (type: bytes)
Instance Variable 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__ Convert a path string to an absolute path if necessary and initialize the FilePath with the result.
Method __getstate__ Support serialization by discarding cached os.stat results and returning everything else.
Method child Create and return a new FilePath representing a path contained by self.
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 Returns the absolute target as a FilePath if self is a link, self otherwise.
Method siblingExtension Attempt to return a path with my name, given the extension at ext.
Method linkTo Creates a symlink to self to at the path in the FilePath linkFilePath.
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 Retrieve the size of this file in bytes.
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 Retrieves the number of hard links to the file.
Method getUserID Returns the user ID of the file's owner.
Method getGroupID Returns the group ID of the file.
Method getPermissions Returns the permissions of the file. Should also work on Windows, however, those permissions may not be what is expected in Windows.
Method exists Check if this FilePath exists.
Method isdir Check if this FilePath refers to a directory.
Method isfile Check if this file path refers to a regular file.
Method isBlockDevice Returns whether the underlying path is a block device.
Method isSocket Returns whether the underlying path is a socket.
Method islink Check if this FilePath points to a symbolic link.
Method isabs Check if this FilePath refers to an absolute path.
Method listdir List the base names of the direct children of this FilePath.
Method splitext Split the file path into a pair (root, ext) such that root + ext == path.
Method __repr__ Undocumented
Method touch 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.
Method remove 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.
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 Retrieve the final component of the file path's path (everything after the final path separator).
Method dirname Retrieve all of the components of the FilePath's path except the last one (everything up to the final path separator).
Method parent A file path for the directory containing the file at this file path.
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 Create the directory the FilePath refers to.
Method requireCreate Sets the alwaysCreate variable.
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 Move self to destination - basically renaming self to whatever destination is named.

Inherited from AbstractFilePath:

Method getContent Retrieve the file-like object for this file path.
Method parents Retrieve an iterator of all the ancestors of this path.
Method children List the children of this path object.
Method walk Yield myself, then each of my children, and each of those children's children in turn.
Method sibling Return a FilePath with the same directory as this instance but with a basename of path.
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.
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: bytes)
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)
def __init__(self, path, alwaysCreate=False): (source)
Convert a path string to an absolute path if necessary and initialize the FilePath with the result.
def __getstate__(self): (source)
Support serialization by discarding cached os.stat results and returning everything else.
def child(self, path): (source)
Create and return a new FilePath representing a path contained by self.
ParameterspathThe base name of the new FilePath. If this contains directory separators or parent references it will be rejected. (type: bytes)
ReturnsThe child path. (type: FilePath)
RaisesInsecurePathIf the result of combining this path with path would result in a path which is not a direct child of this path.
def preauthChild(self, path): (source)
Use me if path might have slashes in it, but you know they're safe.
ParameterspathA relative path (ie, a path not starting with "/") which will be interpreted as a child or descendant of this path. (type: bytes)
ReturnsThe child path. (type: FilePath)
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.

ReturnsNone or the child path. (type: types.NoneType or FilePath)
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).

ReturnsFilePath of the target path. (type: FilePath)
RaisesLinkErrorif links are not supported or links are cyclical.
def siblingExtension(self, ext): (source)
Attempt to return a path with my name, given the extension at ext.
ParametersextFile-extension to search for. (type: str)
ReturnsThe sibling path. (type: FilePath)
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.

ParameterslinkFilePatha 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.

ParametersmodeThe mode to open the file in. Default is "r". (type: str)
ReturnsAn open file object. (type: file)
RaisesAssertionErrorIf "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.
Parametersreraisea boolean. If true, re-raise exceptions from os.stat; otherwise, mark this path as not existing, and remove any cached stat information.
RaisesExceptionIf reraise is True and an exception occurs while reloading metadata.
def changed(self): (source)
Clear any cached information about the state of this path on disk.
Present Since10.1.0
def chmod(self, mode): (source)
Changes the permissions on self, if possible. Propagates errors from os.chmod up.
Parametersmodeinteger representing the new permissions desired (same as the command line chmod) (type: int)
def getsize(self): (source)
Retrieve the size of this file in bytes.
ReturnsThe size of the file at this file path in bytes. (type: int)
RaisesExceptionif the size cannot be obtained.
def getModificationTime(self): (source)
Retrieve the time of last access from this file.
Returnsa number of seconds from the epoch. (type: float)
def getStatusChangeTime(self): (source)
Retrieve the time of the last status change for this file.
Returnsa number of seconds from the epoch. (type: float)
def getAccessTime(self): (source)
Retrieve the time that this file was last accessed.
Returnsa 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.
Returnsa number representing the file serial number (type: int)
RaisesNotImplementedErrorif the platform is Windows, since the inode number would be a dummy value for all files in Windows
Present Since11.0
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.
Returnsa number representing the device (type: int)
RaisesNotImplementedErrorif the platform is Windows, since the device number would be 0 for all partitions on a Windows platform
Present Since11.0
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.

Returnsthe number of hard links to the file (type: int)
RaisesNotImplementedErrorif 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 Since11.0
def getUserID(self): (source)
Returns the user ID of the file's owner.
Returnsthe user ID of the file's owner (type: int)
RaisesNotImplementedErrorif the platform is Windows, since the UID is always 0 on Windows
Present Since11.0
def getGroupID(self): (source)
Returns the group ID of the file.
Returnsthe group ID of the file (type: int)
RaisesNotImplementedErrorif the platform is Windows, since the GID is always 0 on windows
Present Since11.0
def getPermissions(self): (source)
Returns the permissions of the file. Should also work on Windows, however, those permissions may not be what is expected in Windows.
Returnsthe permissions for the file (type: Permissions)
Present Since11.1
def exists(self): (source)
Check if this FilePath exists.
ReturnsTrue if the stats of path can be retrieved successfully, False in the other cases. (type: bool)
def isdir(self): (source)
Check if this FilePath refers to a directory.
ReturnsTrue if this FilePath refers to a directory, False otherwise. (type: bool)
def isfile(self): (source)
Check if this file path refers to a regular file.
ReturnsTrue if this FilePath points to a regular file (not a directory, socket, named pipe, etc), False otherwise. (type: bool)
def isBlockDevice(self): (source)
Returns whether the underlying path is a block device.
ReturnsTrue if it is a block device, False otherwise (type: bool)
Present Since11.1
def isSocket(self): (source)
Returns whether the underlying path is a socket.
ReturnsTrue if it is a socket, False otherwise (type: bool)
Present Since11.1
def islink(self): (source)
Check if this FilePath points to a symbolic link.
ReturnsTrue if this FilePath points to a symbolic link, False otherwise. (type: bool)
def isabs(self): (source)
Check if this FilePath refers to an absolute path.

This always returns True.

ReturnsTrue, always. (type: bool)
def listdir(self): (source)
List the base names of the direct children of this FilePath.
ReturnsA list of bytes giving the names of the contents of the directory this FilePath refers to. These names are relative to this FilePath. (type: list)
RaisesAnything the platform os.listdir implementation might raise (typically OSError).
def splitext(self): (source)
Split the file path into a pair (root, ext) such that root + ext == path.
ReturnsTuple where the first item is the filename and second item is the file extension. See Python docs for os.path.splitext. (type: tuple)
def __repr__(self): (source)
Undocumented
def touch(self): (source)
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.
RaisesExceptionif unable to create or modify the last modification time of the file.
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.
ReturnsNone
def globChildren(self, pattern): (source)
Assuming I am representing a directory, return a list of FilePaths representing my children that match the given pattern.
ParameterspatternA glob pattern to use to match child paths. (type: bytes)
ReturnsA list of matching children. (type: list)
def basename(self): (source)
Retrieve the final component of the file path's path (everything after the final path separator).
ReturnsThe final component of the FilePath's path (Everything after the final path separator). (type: bytes)
def dirname(self): (source)
Retrieve all of the components of the FilePath's path except the last one (everything up to the final path separator).
ReturnsAll of the components of the FilePath's path except the last one (everything up to the final path separator). (type: bytes)
def parent(self): (source)
A file path for the directory containing the file at this file path.
ReturnsA FilePath representing the path which directly contains this FilePath. (type: FilePath)
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.

ParameterscontentThe desired contents of the file at this path. (type: bytes)
extAn 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: bytes)
def __cmp__(self, other): (source)
Undocumented
def createDirectory(self): (source)
Create the directory the FilePath refers to.
RaisesOSErrorIf the directory cannot be created.
See Alsomakedirs
def requireCreate(self, val=1): (source)
Sets the alwaysCreate variable.
ParametersvalTrue or False, indicating whether opening this path will be required to create the file or not. (type: bool)
ReturnsNone
def create(self): (source)
Exclusively create a file, only if this file previously did not exist.
ReturnsA file-like object opened from this path.
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.

ParametersextensionA suffix to append to the created filename. (Note that if you want an extension with a '.' you must include the '.' yourself.) (type: bytes)
Returnsa 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 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.

Parametersdestinationthe destination (a FilePath) to which self should be copied
followLinkswhether 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.

Parametersdestinationthe destination (a FilePath) to which self should be copied
followLinkswhether 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 2013-04-03 11:20:05.