FileAccess Python Reference Documentation

FileAccess

Current Version: 10.0.0

API for reading and writing files, creating and deleting directories, deleting directory trees, splitting and re-joining large files, etc. This is a freeware class. The reason for its existence is that in some programming languages, file I/O API's are limited or difficult to understand/use. This API provides an identical FILE I/O API across all programming languages supported by Chilkat.

Object Creation

obj = chilkat2.FileAccess()

Properties

CurrentDir
string CurrentDir (read-only)

The current working directory of the calling process.

top
DebugLogFilePath
string DebugLogFilePath

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

More Information and Examples
top
EndOfFile
bool EndOfFile (read-only)

Returns True if the current open file is at the end-of-file.

top
FileOpenError
int FileOpenError (read-only)

This property is set by the following methods: FileOpen, OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend. It provides an error code indicating the failure reason. Possible values are:

  1. Success (No error)
  2. Access denied.
  3. File not found.
  4. General (non-specific) open error.
  5. File aleady exists.
  6. Path refers to a directory and the access requested involves writing.
  7. Too many symbolic links were encountered in resolving path.
  8. The process already has the maximum number of files open.
  9. Pathname is too long.
  10. The system limit on the total number of open files has been reached.
  11. Pathname refers to a device special file and no corresponding device exists.
  12. Insufficient kernel memory was available.
  13. Pathname was to be created but the device containing pathname has no room for the new file.
  14. A component used as a directory in pathname is not, in fact, a directory.
  15. Pathname refers to a regular file, too large to be opened (this would be a limitation of the underlying operating system, not a limitation imposed by Chilkat).
  16. Pathname refers to a file on a read-only filesystem and write access was requested.

top
FileOpenErrorMsg
string FileOpenErrorMsg (read-only)

The error message text associated with the FileOpenError code.

top
LastErrorHtml
string LastErrorHtml (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

top
LastErrorText
string LastErrorText (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

top
LastErrorXml
string LastErrorXml (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

top
LastMethodSuccess
bool LastMethodSuccess

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

top
LockFileOnOpen
bool LockFileOnOpen
Introduced in version 9.5.0.80

Note: This property only applies for applications running on Windows.

If True, then the following methods open files for exclusive-access: OpenForAppend, OpenForRead, OpenForReadWrite, OpenForWrite. When a file is opened for exclusive access, it is locked so that no other process may open the file. When the file is closed, the lock is released.

The default value of this property is False.

top
VerboseLogging
bool VerboseLogging

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

top
Version
string Version (read-only)

Version of the component/library, such as "9.5.0.94"

More Information and Examples
top

Methods

AppendAnsi
bool AppendAnsi(string text)

Appends a string using the ANSI character encoding to the currently open file.

Returns True for success, False for failure.

top
AppendBd
bool AppendBd(BinData bd)
Introduced in version 9.5.0.76

Appends the contents of bd to the currently open file.

Returns True for success, False for failure.

top
AppendSb
bool AppendSb(StringBuilder sb, string charset)
Introduced in version 9.5.0.76

Appends the contents of sb using the character encoding (such as "utf-8") specified by charset to the currently open file.

Returns True for success, False for failure.

top
AppendText
bool AppendText(string str, string charset)

Appends a string using the character encoding specified by str to the currently open file.

Returns True for success, False for failure.

top
AppendUnicodeBOM
bool AppendUnicodeBOM()

Appends the 2-byte Unicode BOM (little endian) to the currently open file.

Returns True for success, False for failure.

top
AppendUtf8BOM
bool AppendUtf8BOM()

Appends the 3-byte utf-8 BOM to the currently open file.

Returns True for success, False for failure.

top
DirAutoCreate
bool DirAutoCreate(string filePath)

Same as DirEnsureExists, except the argument is a file path (the last part of the path is a filename and not a directory). Creates all missing directories such that filePath may be created.

Returns True for success, False for failure.

top
DirCreate
bool DirCreate(string dirPath)

Creates a new directory specified by dirPath.

Returns True for success, False for failure.

top
DirDelete
bool DirDelete(string dirPath)

Deletes the directory specified by dirPath. It is only possible to delete a directory if it contains no files or subdirectories.

Returns True for success, False for failure.

top
DirEnsureExists
bool DirEnsureExists(string dirPath)

Creates all directories necessary such that the entire dirPath exists.

Returns True for success, False for failure.

top
DirExists
bool DirExists(string dirPath)
Introduced in version 10.0.0

Returns True if the dirPath exists.

top
FileClose
void FileClose()

Closes the currently open file.

top
FileContentsEqual
bool FileContentsEqual(string filePath1, string filePath2)

Compares the contents of two files and returns True if they are equal and otherwise returns False. The actual contents of the files are only compared if the sizes are equal. The files are not entirely loaded into memory. Instead, they are compared chunk by chunk. This allows for any size files to be compared, regardless of the memory capacity of the computer.

top
FileCopy
bool FileCopy(string existingFilepath, string newFilepath, bool failIfExists)

Copys existingFilepath to newFilepath. If failIfExists is True and newFilepath already exists, then an error is returned.

Returns True for success, False for failure.

top
FileDelete
bool FileDelete(string filePath)

Deletes the file specified by filePath.

Returns True for success, False for failure.

top
FileExists
bool FileExists(string filePath)

Returns True if filePath exists, otherwise returns False.

top
FileExists3
int FileExists3(string path)
Introduced in version 9.5.0.45

Returns 1 if the file exists, 0 if the file does not exist, and -1 if unable to check because of directory permissions or some other error that prevents the ability to obtain the information.

top
FileOpen
bool FileOpen(string filePath, int accessMode, int shareMode, int createDisposition, int attributes)

This method should only be called on Windows operating systems. It's arguments are similar to the Windows Platform SDK function named CreateFile. For Linux, MAC OS X, and other operating system, use the OpenForRead, OpenForWrite, OpenForReadWrite, and OpenForAppend methods.

Opens a file for reading or writing. The arguments mirror the Windows CreateFile function:

Access Modes:
GENERIC_READ	(0x80000000)
GENERIC_WRITE (0x40000000)

Share Modes:
FILE_SHARE_READ(0x00000001)
FILE_SHARE_WRITE(0x00000002)

Create Dispositions
CREATE_NEW          1
CREATE_ALWAYS       2
OPEN_EXISTING       3
OPEN_ALWAYS         4
TRUNCATE_EXISTING   5

// Attributes:
FILE_ATTRIBUTE_READONLY         0x00000001
FILE_ATTRIBUTE_HIDDEN           0x00000002
FILE_ATTRIBUTE_SYSTEM           0x00000004
FILE_ATTRIBUTE_DIRECTORY        0x00000010
FILE_ATTRIBUTE_ARCHIVE          0x00000020
FILE_ATTRIBUTE_NORMAL           0x00000080
FILE_ATTRIBUTE_TEMPORARY	   0x00000100

Returns True for success, False for failure.

top
FileRead
memoryview FileRead(int maxNumBytes)

Reads bytes from the currently open file. maxNumBytes specifies the maximum number of bytes to read. Returns an empty byte array on error.

Returns None on failure

top
FileReadBd
bool FileReadBd(int maxNumBytes, BinData binData)
Introduced in version 9.5.0.64

Reads bytes from the currently open file. maxNumBytes specifies the maximum number of bytes to read. Appends the bytes to the binData.

Returns True for success, False for failure.

top
FileRename
bool FileRename(string existingFilepath, string newFilepath)

Renames a file from existingFilepath to newFilepath.

Returns True for success, False for failure.

top
FileSeek
bool FileSeek(int offset, int origin)

Sets the file pointer for the currently open file. The offset is an offset in bytes from the origin. The origin can be one of the following:

0 = Offset is from beginning of file.
1 = Offset is from current position of file pointer.
2 = Offset is from the end-of-file (offset may be negative).

Returns True for success, False for failure.

top
FileSize
int FileSize(string filePath)

Returns the size, in bytes, of a file. Returns -1 for failure.

Note: This method returns a signed 32-bit integer, which is not large enough to handle files greater than 2GB in size. To handle larger files, call FileSizeStr instead, or call FileSize64. The FileSize64 method was added in Chilkat v9.5.0.88.

Returns True for success, False for failure.

top
FileSize64
int FileSize64(string filePath)
Introduced in version 9.5.0.88

Returns the size, in bytes, of a file. Returns -1 for failure.

top
FileSizeStr
string FileSizeStr(string filePath)
Introduced in version 9.5.0.80

Returns the size of the file in decimal string format.

Returns None on failure

top
FileType
int FileType(string path)
Introduced in version 9.5.0.77

Examines the file at path and returns one of the following values:

-1 = Unable to check because of directory permissions or some error preventing the ability to obtain the information.
0 = File does not exist.
1 = Regular file.
2 = Directory.
3 = Symbolic link.
4 = Windows Shortcut.
99 = Something else.

Additional file types may be added in the future as needed.

More Information and Examples
top
FileWrite
bool FileWrite(memoryview data)

Writes bytes to the currently open file.

Returns True for success, False for failure.

top
FileWriteBd
bool FileWriteBd(BinData binData, int offset, int numBytes)
Introduced in version 9.5.0.64

Writes the contents of binData to the currently open file. To specify the entire contents of binData, set both offset and numBytes equal to 0. To write all remaining data starting at offset, then set numBytes equal to 0.

Returns True for success, False for failure.

More Information and Examples
top
GenBlockId
string GenBlockId(int index, int length, string encoding)
Introduced in version 9.5.0.58

This is purely a utility/convenience method -- initially created to help with block file uploads to Azure Blob storage. It generates a block ID string that is the decimal representation of the index in length chars, and then encoded according to encoding (which can be an encoding such as "base64", "hex", "ascii", etc.) For example, if index = 8, length = 12, and encoding = "base64", then the string "00000012" is returned base64 encoded.

Returns None on failure

top
GetDirectoryName
string GetDirectoryName(string path)
Introduced in version 9.5.0.64

Returns the directory information for the specified path string.

GetDirectoryName('C:\MyDir\MySubDir\myfile.ext') returns 'C:\MyDir\MySubDir\'
GetDirectoryName('C:\MyDir\MySubDir') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir\') returns 'C:\MyDir\'
GetDirectoryName('C:\MyDir') returns 'C:\'
GetDirectoryName('C:\') returns 'C:\'

Returns None on failure

More Information and Examples
top
GetExtension
string GetExtension(string path)
Introduced in version 9.5.0.64

Returns the extension of the specified path string.

GetExtension('C:\mydir.old\myfile.ext') returns '.ext'
GetExtension('C:\mydir.old\') returns ''

Returns None on failure

More Information and Examples
top
GetFileName
string GetFileName(string path)
Introduced in version 9.5.0.64

Returns the file name and extension of the specified path string.

GetFileName('C:\mydir\myfile.ext') returns 'myfile.ext'
GetFileName('C:\mydir\') returns ''

Returns None on failure

More Information and Examples
top
GetFileNameWithoutExtension
string GetFileNameWithoutExtension(string path)
Introduced in version 9.5.0.64

Returns the file name of the specified path string without the extension.

GetFileNameWithoutExtension('C:\mydir\myfile.ext') returns 'myfile'
GetFileNameWithoutExtension('C:\mydir\') returns ''

Returns None on failure

More Information and Examples
top
GetFileTime
CkDateTime GetFileTime(string path, int which)
Introduced in version 9.5.0.71

Gets one of the following date/times for a file:

0: Last-modified
1: Last-access
2: Creation
The "path" argument indicates which time to return. The values can be 0, 1, or 2.

Note: Linux filesystems do not keep a file's creation date/time. In such a case, this method will return the last-modified time.

Returns None on failure

top
GetLastModified
CkDateTime GetLastModified(string path)
Introduced in version 9.5.0.66

Gets the last-modified date/time for a file. The accuracy of the last-modified data is to the number of seconds.

Returns None on failure

top
GetNumBlocks
int GetNumBlocks(int blockSize)
Introduced in version 9.5.0.58

Returns the number of blocks in the currently open file. The number of bytes per block is specified by blockSize. The number of blocks is the file size divided by the blockSize, plus 1 if the file size is not evenly divisible by blockSize. For example, if the currently open file is 60500 bytes, and if the blockSize is 1000 bytes, then this method returns a count of 61 blocks.

Returns -1 if no file is open. Return 0 if the file is completely empty (0 bytes).

top
GetTempFilename
string GetTempFilename(string dirPath, string prefix)

Creates a temporary filepath of the form dirPath\prefix_xxxx.TMP Where "xxxx" are random alpha-numeric chars. The returned filepath is guaranteed to not already exist.

Returns None on failure

top
OpenForAppend
bool OpenForAppend(string filePath)

Opens a file for appending. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten and the file pointer is positioned at the end of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns True for success, False for failure.

top
OpenForRead
bool OpenForRead(string filePath)

Opens a file for reading. The file may contain any type of data (binary or text) and it must already exist. If the open failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns True for success, False for failure.

More Information and Examples
top
OpenForReadWrite
bool OpenForReadWrite(string filePath)

Opens a file for reading/writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will not be overwritten, but the file pointer is positioned at the beginning of the file.

If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns True for success, False for failure.

top
OpenForWrite
bool OpenForWrite(string filePath)

Opens a file for writing. If filePath did not already exists, it is created. When an existing file is opened with this method, the contents will be overwritten. (For example, calling OpenForWrite on an existing file and then immediately closing the file will result in an empty file.) If the open/create failed, then error information will be available in the FileOpenError and FileOpenErrorMsg properties.

Returns True for success, False for failure.

top
ReadBinaryToEncoded
string ReadBinaryToEncoded(string filePath, string encoding)

Reads the entire contents of a binary file and returns it as an encoded string (using an encoding such as Base64, Hex, etc.) The encoding may be one of the following strings: base64, hex, qp, or url.

Returns None on failure

More Information and Examples
top
ReadBlock
memoryview ReadBlock(int blockIndex, int blockSize)
Introduced in version 9.5.0.58

Reads the Nth block of a file, where the size of each block is specified by blockSize. The first block is at blockIndex 0. If the block to be read is the last in the file and there is not enough data to fill an entire block, then the partial block is returned.

Returns None on failure

More Information and Examples
top
ReadBlockBd
bool ReadBlockBd(int blockIndex, int blockSize, BinData bd)
Introduced in version 9.5.0.79

Reads the Nth block of a file, where the size of each block is specified by blockSize. The first block is at blockIndex 0. If the block to be read is the last in the file and there is not enough data to fill an entire block, then the partial block is returned. The file data is appended to the contents of bd.

top
ReadEntireFile
memoryview ReadEntireFile(string filePath)

Reads the entire contents of a binary file and returns the data.

Returns None on failure

top
ReadEntireTextFile
string ReadEntireTextFile(string filePath, string charset)

Reads the entire contents of a text file, interprets the bytes according to the character encoding specified by charset, and returns the text file as a string.

Returns None on failure

top
ReadNextFragment
int ReadNextFragment(bool startAtBeginning, string beginMarker, string endMarker, string charset, StringBuilder sb)
Introduced in version 9.5.0.80

Scans the currently open file (opened by calling OpenForRead) for the next chunk of text delimited by beginMarker and endMarker. The matched text, including the beginMarker and endMarker are appended to sb. The bytes of the text file are interpreted according to charset. If startAtBeginning equals True, then scanning begins at the start of the file. Otherwise scanning begins starting at the byte following the last matched fragment.

The return value of this function is:
0: No match was found.
1: Found the next matching fragment and appended to sb.
-1: Error reading the file.

To support a common need for use with XML files, the beginMarker is "XML tag aware". If the beginMarker is a string such as "", then it will also match "

More Information and Examples
top
ReassembleFile
bool ReassembleFile(string partsDirPath, string partPrefix, string partExtension, string reassembledFilename)

Reassembles a file previously split by the SplitFile method.

Returns True for success, False for failure.

More Information and Examples
top
ReplaceStrings
int ReplaceStrings(string filePath, string charset, string existingString, string replacementString)

Replaces all occurrences of existingString with replacementString in a file. The character encoding, such as utf-8, ansi, etc. is specified by charset.

top
SetCurrentDir
bool SetCurrentDir(string dirPath)

Sets the current working directory for the calling process to dirPath.

Returns True for success, False for failure.

top
SetFileTimes
bool SetFileTimes(string filePath, CkDateTime createTime, CkDateTime lastAccessTime, CkDateTime lastModTime)

Sets the create date/time, the last-access date/time, and the last-modified date/time for a file. For non-Windows filesystems where create times are not implemented, the createTime is ignored.

top
SetLastModified
bool SetLastModified(string filePath, CkDateTime lastModified)

Sets the last-modified date/time for a file.

top
SplitFile
bool SplitFile(string fileToSplit, string partPrefix, string partExtension, int partSize, string destDir)

Splits a file into chunks. To reassemble a split file, see the ReassembleFile method. Please refer to the example below:

Returns True for success, False for failure.

More Information and Examples
top
SymlinkCreate
bool SymlinkCreate(string targetPath, string linkPath)
Introduced in version 9.5.0.77

Creates a symbolic link.

Note: On Windows systems, this is not the same as creating a shortcut. A Windows symbolic link and a Windows shortcut are two different things. Shortcut files are common on Windows, but not symbolic links. Creating a symbolic link requires a special privilege, unless running as administrator. To be able to create symbolic links, your user account or group needs to be listed in secpol.msc → Security Settings → Local Policies → User Rights Assignment → Create symbolic links. However the special setting is not needed when running within the development environment, such as from Visual Studio.

Returns True for success, False for failure.

More Information and Examples
top
SymlinkTarget
string SymlinkTarget(string linkPath)
Introduced in version 9.5.0.77

Returns the full pathname of the file at the end of the linkPath. Also handles Windows shortcut files by returning the absolute path of the target.

Returns None on failure

top
TreeDelete
bool TreeDelete(string path)

Deletes an entire directory tree (all files and sub-directories).

Returns True for success, False for failure.

top
Truncate
bool Truncate()
Introduced in version 9.5.0.80

Truncates the currently open file at the current file position.

Returns True for success, False for failure.

top
WriteEntireFile
bool WriteEntireFile(string filePath, memoryview fileData)

Opens/creates filePath, writes fileData, and closes the file.

Returns True for success, False for failure.

top
WriteEntireTextFile
bool WriteEntireTextFile(string filePath, string textData, string charset, bool includedPreamble)

Opens filePath, writes textData using the character encoding specified by charset, and closes the file. If includedPreamble is True and the charset is Unicode or utf-8, then the BOM is included at the beginning of the file.

Returns True for success, False for failure.

More Information and Examples
top