QFileInfo¶

The QFileInfo class provides system-independent file information. More…

Synopsis¶

Functions¶

def __eq__ (fileinfo)
def __ne__ (fileinfo)
def __reduce__ ()
def absoluteDir ()
def absoluteFilePath ()
def absolutePath ()
def baseName ()
def birthTime ()
def bundleName ()
def caching ()
def canonicalFilePath ()
def canonicalPath ()
def completeBaseName ()
def completeSuffix ()
def created ()
def dir ()
def exists ()
def fileName ()
def filePath ()
def group ()
def groupId ()
def isAbsolute ()
def isBundle ()
def isDir ()
def isExecutable ()
def isFile ()
def isHidden ()
def isNativePath ()
def isReadable ()
def isRelative ()
def isRoot ()
def isSymLink ()
def isWritable ()
def lastModified ()
def lastRead ()
def makeAbsolute ()
def metadataChangeTime ()
def owner ()
def ownerId ()
def path ()
def readLink ()
def refresh ()
def setCaching (on)
def setFile (dir, file)
def setFile (file)
def setFile (file)
def size ()
def suffix ()
def swap (other)
def symLinkTarget ()

Static functions¶

def exists (file)

Detailed Description¶

QFileInfo provides information about a file’s name and position (path) in the file system, its access rights and whether it is a directory or symbolic link, etc. The file’s size and last modified/read times are also available. QFileInfo can also be used to obtain information about a Qt resource .

A QFileInfo can point to a file with either a relative or an absolute file path. Absolute file paths begin with the directory separator “/” (or with a drive specification on Windows). Relative file names begin with a directory name or a file name and specify a path relative to the current working directory. An example of an absolute path is the string “/tmp/quartz”. A relative path might look like “src/fatlib”. You can use the function isRelative() to check whether a QFileInfo is using a relative or an absolute file path. You can call the function makeAbsolute() to convert a relative QFileInfo ‘s path to an absolute path.

The file that the QFileInfo works on is set in the constructor or later with setFile() . Use exists() to see if the file exists and size() to get its size.

The file’s type is obtained with isFile() , isDir() and isSymLink() . The symLinkTarget() function provides the name of the file the symlink points to.

On Unix (including macOS and iOS), the symlink has the same size() has the file it points to, because Unix handles symlinks transparently; similarly, opening a symlink using QFile effectively opens the link’s target. For example:
info1 = QFileInfo("/home/bob/bin/untabify")
info1.isSymLink()           # returns true
info1.absoluteFilePath()    # returns "/home/bob/bin/untabify"
info1.size()                # returns 56201
info1.symLinkTarget()       # returns "/opt/pretty++/bin/untabify"

info2 = QFileInfo(info1.symLinkTarget())
info1.isSymLink()           # returns False
info1.absoluteFilePath()    # returns "/opt/pretty++/bin/untabify"
info1.size()                # returns 56201
On Windows, symlinks (shortcuts) are .lnk files. The reported size() is that of the symlink (not the link’s target), and opening a symlink using QFile opens the .lnk file. For example:
info1 = QFileInfo("C:\\Documents and Settings\\Bob\\untabify.lnk")
info1.isSymLink()           # returns True
info1.absoluteFilePath()    # returns "C:/Documents and Settings/Bob/untabify.lnk"
info1.size()                # returns 743
info1.symLinkTarget()       # returns "C:/Pretty++/untabify"

info2 = QFileInfo(info1.symLinkTarget())
info1.isSymLink()           # returns False
info1.absoluteFilePath()    # returns "C:/Pretty++/untabify"
info1.size()                # returns 63942
Elements of the file’s name can be extracted with path() and fileName() . The fileName() ‘s parts can be extracted with baseName() , suffix() or completeSuffix() . QFileInfo objects to directories created by Qt classes will not have a trailing file separator. If you wish to use trailing separators in your own file info objects, just append one to the file name given to the constructors or setFile() .

The file’s dates are returned by created() , lastModified() , lastRead() and fileTime() . Information about the file’s access permissions is obtained with isReadable() , isWritable() and isExecutable() . The file’s ownership is available from owner() , ownerId() , group() and groupId() . You can examine a file’s permissions and ownership in a single statement using the permission() function.

Note

On NTFS file systems, ownership and permissions checking is disabled by default for performance reasons. To enable it, include the following line:
extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;
Permission checking is then turned on and off by incrementing and decrementing qt_ntfs_permission_lookup by 1.
qt_ntfs_permission_lookup += 1 // turn checking on
qt_ntfs_permission_lookup += 1 // turn it off again

Performance Issues¶

Some of QFileInfo ‘s functions query the file system, but for performance reasons, some functions only operate on the file name itself. For example: To return the absolute path of a relative file name, absolutePath() has to query the file system. The path() function, however, can work on the file name directly, and so it is faster.

Note

To speed up performance, QFileInfo caches information about the file.

Because files can be changed by other users or programs, or even by other parts of the same program, there is a function that refreshes the file information: refresh() . If you want to switch off a QFileInfo ‘s caching and force it to access the file system every time you request information from it call setCaching (false).

See also

QDir QFile

class QFileInfo¶

QFileInfo(dir, file)

QFileInfo(file)

QFileInfo(fileinfo)

QFileInfo(file)

param dir

QDir

param fileinfo

QFileInfo

param file

unicode

Constructs an empty QFileInfo object.

Note that an empty QFileInfo object contain no file reference.

See also

setFile()

Constructs a new QFileInfo that gives information about the given file in the directory dir .

If dir has a relative path, the QFileInfo will also have a relative path.

If file is an absolute path, then the directory specified by dir will be disregarded.

See also

isRelative()

PySide2.QtCore.QFileInfo.__reduce__()¶

Return type: PyObject

PySide2.QtCore.QFileInfo.absoluteDir()¶

Return type: QDir

Returns the file’s absolute path as a QDir object.

PySide2.QtCore.QFileInfo.absoluteFilePath()¶

Return type: unicode

Returns an absolute path including the file name.

The absolute path name consists of the full path and the file name. On Unix this will always begin with the root, ‘/’, directory. On Windows this will always begin ‘D:/’ where D is a drive letter, except for network shares that are not mapped to a drive letter, in which case the path will begin ‘//sharename/’. QFileInfo will uppercase drive letters. Note that QDir does not do this. The code snippet below shows this.

fi = QFileInfo("c:/temp/foo") => fi.absoluteFilePath() => "C:/temp/foo"

This function returns the same as filePath() , unless isRelative() is true. In contrast to canonicalFilePath() , symbolic links or redundant “.” or “..” elements are not necessarily removed.

Warning

If filePath() is empty the behavior of this function is undefined.

PySide2.QtCore.QFileInfo.absolutePath()¶

Return type: unicode

Returns a file’s path absolute path. This doesn’t include the file name.

On Unix the absolute path will always begin with the root, ‘/’, directory. On Windows this will always begin ‘D:/’ where D is a drive letter, except for network shares that are not mapped to a drive letter, in which case the path will begin ‘//sharename/’.

In contrast to canonicalPath() symbolic links or redundant “.” or “..” elements are not necessarily removed.

Warning

If filePath() is empty the behavior of this function is undefined.

PySide2.QtCore.QFileInfo.baseName()¶

Return type: unicode

Returns the base name of the file without the path.

The base name consists of all characters in the file up to (but not including) the first ‘.’ character.

Example:

fi = QFileInfo("/tmp/archive.tar.gz")
base = fi.baseName()                    # base = "archive"

The base name of a file is computed equally on all platforms, independent of file naming conventions (e.g., “.bashrc” on Unix has an empty base name, and the suffix is “bashrc”).

PySide2.QtCore.QFileInfo.birthTime()¶

Return type: QDateTime

Returns the date and time when the file was created / born.

If the file birth time is not available, this function returns an invalid QDateTime .

PySide2.QtCore.QFileInfo.bundleName()¶

Return type: unicode

Returns the name of the bundle.

On macOS and iOS this returns the proper localized name for a bundle if the path isBundle() . On all other platforms an empty QString is returned.

Example:

fi = QFileInfo("/Applications/Safari.app")
bundle = fi.bundleName()                # name = "Safari"

PySide2.QtCore.QFileInfo.caching()¶

Return type: bool

Returns true if caching is enabled; otherwise returns false .

See also

setCaching() refresh()

PySide2.QtCore.QFileInfo.canonicalFilePath()¶

Return type: unicode

Returns the canonical path including the file name, i.e. an absolute path without symbolic links or redundant “.” or “..” elements.

If the file does not exist, returns an empty string.

PySide2.QtCore.QFileInfo.canonicalPath()¶

Return type: unicode

Returns the file’s path canonical path (excluding the file name), i.e. an absolute path without symbolic links or redundant “.” or “..” elements.

If the file does not exist, returns an empty string.

See also

path() absolutePath()

PySide2.QtCore.QFileInfo.completeBaseName()¶

Return type: unicode

Returns the complete base name of the file without the path.

The complete base name consists of all characters in the file up to (but not including) the last ‘.’ character.

Example:

fi = QFileInfo("/tmp/archive.tar.gz")
base = fi.completeBaseName()            # base = "archive.tar"

PySide2.QtCore.QFileInfo.completeSuffix()¶

Return type: unicode

Returns the complete suffix (extension) of the file.

The complete suffix consists of all characters in the file after (but not including) the first ‘.’.

Example:

fi = QFileInfo("/tmp/archive.tar.gz")
ext = fi.completeSuffix()               # ext = "tar.gz"

PySide2.QtCore.QFileInfo.created()¶

Return type: QDateTime

Returns the date and time when the file was created, the time its metadata was last changed or the time of last modification, whichever one of the three is available (in that order).

This function is deprecated. Instead, use the birthTime() function to get the time the file was created, metadataChangeTime() to get the time its metadata was last changed, or lastModified() to get the time it was last modified.

PySide2.QtCore.QFileInfo.dir()¶

Return type: QDir

Returns the path of the object’s parent directory as a QDir object.

Note

The QDir returned always corresponds to the object’s parent directory, even if the QFileInfo represents a directory.

For each of the following, returns the QDir "~/examples/191697" .

fileInfo1 = QFileInfo("~/examples/191697/.")
fileInfo2 = QFileInfo("~/examples/191697/..")
fileInfo3 = QFileInfo("~/examples/191697/main.cpp")

For each of the following, returns the QDir "." .

fileInfo4 = QFileInfo(".")
fileInfo5 = QFileInfo("..")
fileInfo6 = QFileInfo("main.cpp")

PySide2.QtCore.QFileInfo.exists()¶

Return type: bool

Returns true if the file exists; otherwise returns false .

Note

If the file is a symlink that points to a non-existing file, false is returned.

static PySide2.QtCore.QFileInfo.exists(file)

Parameters: file – unicode
Return type: bool

Returns true if the file exists; otherwise returns false .

Note

If file is a symlink that points to a non-existing file, false is returned.

Note

Using this function is faster than using QFileInfo(file).exists() for file system access.

PySide2.QtCore.QFileInfo.fileName()¶

Return type: unicode

Returns the name of the file, excluding the path.

Example:

fi = QFileInfo("/tmp/archive.tar.gz")
name = fi.fileName()                    # name = "archive.tar.gz"

Note that, if this QFileInfo object is given a path ending in a slash, the name of the file is considered empty.

PySide2.QtCore.QFileInfo.filePath()¶

Return type: unicode

Returns the file name, including the path (which may be absolute or relative).

PySide2.QtCore.QFileInfo.group()¶

Return type: unicode

Returns the group of the file. On Windows, on systems where files do not have groups, or if an error occurs, an empty string is returned.

This function can be time consuming under Unix (in the order of milliseconds).

See also

groupId() owner() ownerId()

PySide2.QtCore.QFileInfo.groupId()¶

Return type: uint

Returns the id of the group the file belongs to.

On Windows and on systems where files do not have groups this function always returns (uint) -2.

See also

group() owner() ownerId()

PySide2.QtCore.QFileInfo.isAbsolute()¶

Return type: bool

Returns true if the file path name is absolute, otherwise returns false if the path is relative.

See also

isRelative()

PySide2.QtCore.QFileInfo.isBundle()¶

Return type: bool

Returns true if this object points to a bundle or to a symbolic link to a bundle on macOS and iOS; otherwise returns false .

See also

isDir() isSymLink() isFile()

PySide2.QtCore.QFileInfo.isDir()¶

Return type: bool

Returns true if this object points to a directory or to a symbolic link to a directory; otherwise returns false .

See also

isFile() isSymLink() isBundle()

PySide2.QtCore.QFileInfo.isExecutable()¶

Return type: bool

Returns true if the file is executable; otherwise returns false .

See also

isReadable() isWritable() permission()

PySide2.QtCore.QFileInfo.isFile()¶

Return type: bool

Returns true if this object points to a file or to a symbolic link to a file. Returns false if the object points to something which isn’t a file, such as a directory.

See also

isDir() isSymLink() isBundle()

PySide2.QtCore.QFileInfo.isHidden()¶

Return type: bool

Returns true if this is a `hidden’ file; otherwise returns false .

Note

This function returns true for the special entries “.” and “..” on Unix, even though entryList threats them as shown.

PySide2.QtCore.QFileInfo.isNativePath()¶

Return type: bool

Returns true if the file path can be used directly with native APIs. Returns false if the file is otherwise supported by a virtual file system inside Qt, such as the Qt Resource System .

Note

Native paths may still require conversion of path separators and character encoding, depending on platform and input requirements of the native API.

PySide2.QtCore.QFileInfo.isReadable()¶

Return type: bool

Returns true if the user can read the file; otherwise returns false .

Note

If the NTFS permissions check has not been enabled, the result on Windows will merely reflect whether the file exists.

See also

isWritable() isExecutable() permission()

PySide2.QtCore.QFileInfo.isRelative()¶

Return type: bool

Returns true if the file path name is relative, otherwise returns false if the path is absolute (e.g. under Unix a path is absolute if it begins with a “/”).

See also

isAbsolute()

PySide2.QtCore.QFileInfo.isRoot()¶

Return type: bool

Returns true if the object points to a directory or to a symbolic link to a directory, and that directory is the root directory; otherwise returns false .

PySide2.QtCore.QFileInfo.isSymLink()¶

Return type: bool

Returns true if this object points to a symbolic link; otherwise returns false .

Symbolic links exist on Unix (including macOS and iOS) and Windows and are typically created by the ln -s or mklink commands, respectively. Opening a symbolic link effectively opens the link's target .

In addition, true will be returned for shortcuts (*.lnk files) on Windows. Opening those will open the .lnk file itself.

Example:

info = QFileInfo(fileName)
if info.isSymLink():
    fileName = info.symLinkTarget()

Note

If the symlink points to a non existing file, exists() returns false.

See also

isFile() isDir() symLinkTarget()

PySide2.QtCore.QFileInfo.isWritable()¶

Return type: bool

Returns true if the user can write to the file; otherwise returns false .

Note

If the NTFS permissions check has not been enabled, the result on Windows will merely reflect whether the file is marked as Read Only.

See also

isReadable() isExecutable() permission()

PySide2.QtCore.QFileInfo.lastModified()¶

Return type: QDateTime

Returns the date and local time when the file was last modified.

PySide2.QtCore.QFileInfo.lastRead()¶

Return type: QDateTime

Returns the date and local time when the file was last read (accessed).

On platforms where this information is not available, returns the same as lastModified() .

PySide2.QtCore.QFileInfo.makeAbsolute()¶

Return type: bool

Converts the file’s path to an absolute path if it is not already in that form. Returns true to indicate that the path was converted; otherwise returns false to indicate that the path was already absolute.

See also

filePath() isRelative()

PySide2.QtCore.QFileInfo.metadataChangeTime()¶

Return type: QDateTime

Returns the date and time when the file metadata was changed. A metadata change occurs when the file is created, but it also occurs whenever the user writes or sets inode information (for example, changing the file permissions).

See also

lastModified() lastRead()

PySide2.QtCore.QFileInfo.__ne__(fileinfo)¶

Parameters: fileinfo – QFileInfo
Return type: bool

Returns true if this QFileInfo object refers to a different file than the one specified by fileinfo ; otherwise returns false .

See also

operator==()

PySide2.QtCore.QFileInfo.__eq__(fileinfo)¶

Parameters: fileinfo – QFileInfo
Return type: bool

Returns true if this QFileInfo object refers to a file in the same location as fileinfo ; otherwise returns false .

Note that the result of comparing two empty QFileInfo objects, containing no file references (file paths that do not exist or are empty), is undefined.

Warning

This will not compare two different symbolic links pointing to the same file.

Warning

Long and short file names that refer to the same file on Windows are treated as if they referred to different files.

See also

operator!=()

PySide2.QtCore.QFileInfo.owner()¶

Return type: unicode

Returns the owner of the file. On systems where files do not have owners, or if an error occurs, an empty string is returned.

This function can be time consuming under Unix (in the order of milliseconds). On Windows, it will return an empty string unless the NTFS permissions check has been enabled.

See also

ownerId() group() groupId()

PySide2.QtCore.QFileInfo.ownerId()¶

Return type: uint

Returns the id of the owner of the file.

On Windows and on systems where files do not have owners this function returns ((uint) -2).

See also

owner() group() groupId()

PySide2.QtCore.QFileInfo.path()¶

Return type: unicode

Returns the file’s path. This doesn’t include the file name.

Note that, if this QFileInfo object is given a path ending in a slash, the name of the file is considered empty and this function will return the entire path.

PySide2.QtCore.QFileInfo.readLink()¶

Return type: unicode

Use symLinkTarget() instead.

PySide2.QtCore.QFileInfo.refresh()¶: Refreshes the information about the file, i.e. reads in information from the file system the next time a cached property is fetched.

PySide2.QtCore.QFileInfo.setCaching(on)¶

Parameters: on – bool

If enable is true, enables caching of file information. If enable is false caching is disabled.

When caching is enabled, QFileInfo reads the file information from the file system the first time it’s needed, but generally not later.

Caching is enabled by default.

See also

refresh() caching()

PySide2.QtCore.QFileInfo.setFile(dir, file)¶

Parameters

dir – QDir
file – unicode

This is an overloaded function.

Sets the file that the QFileInfo provides information about to file in directory dir .

If file includes a relative path, the QFileInfo will also have a relative path.

See also

isRelative()

PySide2.QtCore.QFileInfo.setFile(file)

Parameters: file – QFile

PySide2.QtCore.QFileInfo.setFile(file)

Parameters: file – unicode

PySide2.QtCore.QFileInfo.size()¶

Return type: qint64

Returns the file size in bytes. If the file does not exist or cannot be fetched, 0 is returned.

See also

exists()

PySide2.QtCore.QFileInfo.suffix()¶

Return type: unicode

Returns the suffix (extension) of the file.

The suffix consists of all characters in the file after (but not including) the last ‘.’.

Example:

fi = QFileInfo("/tmp/archive.tar.gz")
ext = fi.suffix();                      # ext = "gz"

The suffix of a file is computed equally on all platforms, independent of file naming conventions (e.g., “.bashrc” on Unix has an empty base name, and the suffix is “bashrc”).

PySide2.QtCore.QFileInfo.swap(other)¶

Parameters: other – QFileInfo

Swaps this file info with other . This function is very fast and never fails.

PySide2.QtCore.QFileInfo.symLinkTarget()¶

Return type: unicode

Returns the absolute path to the file or directory a symbolic link points to, or an empty string if the object isn’t a symbolic link.

This name may not represent an existing file; it is only a string. exists() returns true if the symlink points to an existing file.

Qt Documentation

Table of Contents

QFileInfo¶

Synopsis¶

Functions¶

Static functions¶

Detailed Description¶

Performance Issues¶