Gzip Python Reference Documentation

Gzip

Current Version: 10.0.0

GZip compression component.

Object Creation

obj = chilkat2.Gzip()

Properties

AbortCurrent
bool AbortCurrent
Introduced in version 9.5.0.58

When set to True, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to False when the next method is called. When the abort occurs, this property is reset to False. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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Comment
string Comment

Specifies an optional comment string that can be embedded within the .gz when any Compress* method is called.

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CompressionLevel
int CompressionLevel
Introduced in version 9.5.0.50

The compression level to be used when compressing. The default is 6, which is the typical value used for zip utility programs when compressing data. The compression level may range from 0 (no compression) to 9 (the most compression). The benefits of trying to increase compression may not be worth the added expense in compression time. In many cases (which is data dependent), the improvement in compression is minimal while the increase in computation time is significant.

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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.

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ExtraData
memoryview ExtraData

Optional extra-data that can be included within a .gz when a Compress* method is called.

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Filename
string Filename

The filename that is embedded within the .gz during any Compress* method call. When extracting from a .gz using applications such as WinZip, this will be the filename that is created.

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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.

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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.

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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.

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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.

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LastModStr
string LastModStr

The same as the LastMod property, but allows the date/time to be get/set in RFC822 string format.

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UseCurrentDate
bool UseCurrentDate

If set to True, the file produced by an Uncompress* method will use the current date/time for the last-modification date instead of the date/time found within the Gzip format.

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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.

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Version
string Version (read-only)

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

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Methods

CompressBd
bool CompressBd(BinData binDat)
Introduced in version 9.5.0.67

In-place gzip the contents of binDat.

Returns True for success, False for failure.

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CompressBdAsync (1)
Task CompressBdAsync(BinData binDat)
Introduced in version 9.5.0.67

Creates an asynchronous task to call the CompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressFile
bool CompressFile(string inFilename, string destPath)

Compresses a file to create a GZip compressed file (.gz).

Returns True for success, False for failure.

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CompressFileAsync (1)
Task CompressFileAsync(string inFilename, string destPath)

Creates an asynchronous task to call the CompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressFile2
bool CompressFile2(string inFilename, string embeddedFilename, string destPath)

Compresses a file to create a GZip compressed file (.gz). inFilename is the actual filename on disk. embeddedFilename is the filename to be embedded in the .gz such that when it is un-gzipped, this is the name of the file that will be created.

Returns True for success, False for failure.

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CompressFile2Async (1)
Task CompressFile2Async(string inFilename, string embeddedFilename, string destPath)

Creates an asynchronous task to call the CompressFile2 method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressFileToMem
memoryview CompressFileToMem(string inFilename)

Gzip compresses a file to an in-memory image of a .gz file.

Note: There is a 4GB size limitation. The compressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns None on failure

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CompressFileToMemAsync (1)
Task CompressFileToMemAsync(string inFilename)

Creates an asynchronous task to call the CompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressMemory
memoryview CompressMemory(memoryview inData)

Compresses in-memory data to an in-memory image of a .gz file.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns None on failure

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CompressMemoryAsync (1)
Task CompressMemoryAsync(memoryview inData)

Creates an asynchronous task to call the CompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressMemToFile
bool CompressMemToFile(memoryview inData, string destPath)

Gzip compresses and creates a .gz file from in-memory data.

Returns True for success, False for failure.

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CompressMemToFileAsync (1)
Task CompressMemToFileAsync(memoryview inData, string destPath)

Creates an asynchronous task to call the CompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressString
memoryview CompressString(string inStr, string destCharset)

Gzip compresses a string and writes the output to a byte array. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns None on failure

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CompressStringAsync (1)
Task CompressStringAsync(string inStr, string destCharset)

Creates an asynchronous task to call the CompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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CompressStringENC
string CompressStringENC(string inStr, string charset, string encoding)

The same as CompressString, except the binary output is returned in encoded string form according to the encoding. The encoding can be any of the following: "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns None on failure

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CompressStringToFile
bool CompressStringToFile(string inStr, string destCharset, string destPath)

Gzip compresses a string and writes the output to a .gz compressed file. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns True for success, False for failure.

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CompressStringToFileAsync (1)
Task CompressStringToFileAsync(string inStr, string destCharset, string destPath)

Creates an asynchronous task to call the CompressStringToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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Decode
memoryview Decode(string encodedStr, string encoding)

Decodes an encoded string and returns the original data. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns None on failure

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DeflateStringENC
string DeflateStringENC(string inString, string charsetName, string outputEncoding)

Provides the ability to use the zip/gzip's deflate algorithm directly to compress a string. Internal to this method, inString is first converted to the charset specified by charsetName. The data is then compressed using the deflate compression algorithm. The binary output is then encoded according to outputEncoding. Possible values for outputEncoding are "hex", "base64", "url", and "quoted-printable".

Note: The output of this method is compressed data with no Gzip file format. Use the Compress* methods to produce Gzip file format output.

Returns None on failure

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Encode
string Encode(memoryview byteData, string encoding)

Encodes binary data to a printable string. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns None on failure

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ExamineFile
bool ExamineFile(string inGzFilename)

Determines if the inGzFilename is a Gzip formatted file. Returns True if it is a Gzip formatted file, otherwise returns False.

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ExamineMemory
bool ExamineMemory(memoryview inGzData)

Determines if the in-memory bytes (inGzData) contain a Gzip formatted file. Returns True if it is Gzip format, otherwise returns False.

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GetDt
CkDateTime GetDt()

Gets the last-modification date/time to be embedded within the .gz.

Returns None on failure

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InflateStringENC
string InflateStringENC(string inString, string convertFromCharset, string inputEncoding)

This the reverse of DeflateStringENC.

The input string is first decoded according to inputEncoding. (Possible values for inputEncoding are "hex", "base64", "url", and "quoted-printable".) The compressed data is then inflated, and the result is then converted from convertFromCharset (if necessary) to return a string.

Returns None on failure

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LoadTaskCaller
bool LoadTaskCaller(Task task)
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

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ReadFile
memoryview ReadFile(string path)

Reads a binary file into memory and returns the byte array. Note: This method does not parse a Gzip, it is only a convenience method for reading a binary file into memory.

Returns None on failure

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SetDt
bool SetDt(CkDateTime dt)

Sets the last-modification date/time to be embedded within the .gz when a Compress* method is called. If not explicitly set, the current system date/time is used.

Returns True for success, False for failure.

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UncompressBd
bool UncompressBd(BinData binDat)
Introduced in version 9.5.0.67

In-place ungzip the contents of binDat.

Returns True for success, False for failure.

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UncompressBdAsync (1)
Task UncompressBdAsync(BinData binDat)
Introduced in version 9.5.0.67

Creates an asynchronous task to call the UncompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressFile
bool UncompressFile(string srcPath, string destPath)

Un-Gzips a .gz file. The output filename is specified by the 2nd argument and not by the filename embedded within the .gz.

Returns True for success, False for failure.

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UncompressFileAsync (1)
Task UncompressFileAsync(string srcPath, string destPath)

Creates an asynchronous task to call the UncompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressFileToMem
memoryview UncompressFileToMem(string inFilename)

Un-Gzips a .gz file directly to memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns None on failure

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UncompressFileToMemAsync (1)
Task UncompressFileToMemAsync(string inFilename)

Creates an asynchronous task to call the UncompressFileToMem method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressFileToString
string UncompressFileToString(string gzFilename, string charset)

Uncompresses a .gz file that contains a text file. The contents of the text file are returned as a string. The character encoding of the text file is specified by charset. Typical charsets are "iso-8859-1", "utf-8", "windows-1252", "shift_JIS", "big5", etc.

Returns None on failure

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UncompressFileToStringAsync (1)
Task UncompressFileToStringAsync(string gzFilename, string charset)

Creates an asynchronous task to call the UncompressFileToString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressMemory
memoryview UncompressMemory(memoryview inData)

Un-Gzips from an in-memory image of a .gz file directly into memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns None on failure

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UncompressMemoryAsync (1)
Task UncompressMemoryAsync(memoryview inData)

Creates an asynchronous task to call the UncompressMemory method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressMemToFile
bool UncompressMemToFile(memoryview inData, string destPath)

Un-Gzips from an in-memory image of a .gz file to a file.

Returns True for success, False for failure.

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UncompressMemToFileAsync (1)
Task UncompressMemToFileAsync(memoryview inData, string destPath)

Creates an asynchronous task to call the UncompressMemToFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressString
string UncompressString(memoryview inData, string inCharset)

The reverse of CompressString.

The bytes in inData are uncompressed, then converted from inCharset (if necessary) to return a string.

Returns None on failure

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UncompressStringAsync (1)
Task UncompressStringAsync(memoryview inData, string inCharset)

Creates an asynchronous task to call the UncompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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UncompressStringENC
string UncompressStringENC(string inStr, string charset, string encoding)

The same as UncompressString, except the compressed data is provided in encoded string form based on the value of encoding. The encoding can be "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns None on failure

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UnTarGz
bool UnTarGz(string tgzFilename, string destDir, bool bNoAbsolute)

Unpacks a .tar.gz file. The ungzip and untar occur in streaming mode. There are no temporary files and the memory footprint is constant (and small) while untarring. bNoAbsolute may be True or False. A value of True protects from untarring to absolute paths. (For example, imagine the trouble if the tar contains files with absolute paths beginning with /Windows/system32)

Returns True for success, False for failure.

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UnTarGzAsync (1)
Task UnTarGzAsync(string tgzFilename, string destDir, bool bNoAbsolute)

Creates an asynchronous task to call the UnTarGz method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Returns None on failure

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WriteFile
bool WriteFile(string path, memoryview binaryData)

A convenience method for writing a binary byte array to a file.

Returns True for success, False for failure.

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XfdlToXml
string XfdlToXml(string xfldData)

Converts base64-gzip .xfdl data to a decompressed XML string. The xfldData contains the base64 data. This method returns the decoded/decompressed XML string.

Returns None on failure

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