CDPL.Util.GZipIStream Class Reference

Input stream that transparently decompresses gzip-compressed data. More...

Inheritance diagram for CDPL.Util.GZipIStream:

Public Member Functions
None	__init__ ()
	Contructs the GZipIStream instance.
None	__init__ (Base.IStream is)
	Constructs a GZipIStream instance that will read the compressed data from the input stream is. More...
str	readline (int size=-1)
	Reads one entire line. More...
list	readlines (int size=-1)
	Reads lines until EOF and returns a list containing the lines thus read. More...
GZipIStream	xreadlines ()
	Returns the stream instance. More...
str	read (int size=-1)
	Reads at most size bytes. More...
int	tell ()
	Returns the current read position. More...
int	tellr ()
	Returns the current read position. More...
None	seek (int offs, int whence=0)
	Sets the current read position. More...
None	seekr (int offs, int whence=0)
	Sets the current read position. More...
str	next ()
	Reads and returns the next line. More...
bool	isClosed ()
	Tells whether the stream has been closed. More...
str	getOpenModeString ()
	Returns the open mode string that was provided as argument to the constructor. More...
OpenMode	getOpenModeFlags ()
	Returns the open mode flags that were provided as argument to the constructor. More...
None	close ()
	Closes the stream. More...
None	open (Base.IStream is)
	Sets the input stream that provides the compressed data. More...
GZipIStream	__iter__ ()
	Returns the stream instance. More...
Public Member Functions inherited from CDPL.Base.IStream
int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...

Properties
	closed = property(isClosed)
	mode = property(getOpenModeString)
	modeFlags = property(getOpenModeFlags)
Properties inherited from CDPL.Base.IStream
	objectID = property(getObjectID)

Additional Inherited Members
Static Public Attributes inherited from CDPL.Base.IStream
	STD_IN = _HIDDEN_VALUE_
	The standard input stream of the current process.

Detailed Description

Input stream that transparently decompresses gzip-compressed data.

Constructor & Destructor Documentation

__init__()

None CDPL.Util.GZipIStream.__init__

(

Base.IStream

is

)

Constructs a GZipIStream instance that will read the compressed data from the input stream is.

Parameters

is	The input stream to read from.

Member Function Documentation

readline()

str CDPL.Util.GZipIStream.readline

(

int

size = -1

)

Reads one entire line.

A trailing newline character is kept in the string (but may be absent when a file ends with an incomplete line). If the size argument is present and non-negative, it is a maximum byte count (including the trailing newline) and an incomplete line may be returned. When size is not 0, an empty string is returned only if EOF is encountered immediately.

Parameters

size	If present and non-negative, specifies the maximum number of bytes to read (including the trailing newline).

Returns

A string holding the read line.

readlines()

list CDPL.Util.GZipIStream.readlines

(

int

size = -1

)

Reads lines until EOF and returns a list containing the lines thus read.

If the optional size argument is present and non-negative, instead of reading up to EOF, whole lines totalling approximately size bytes are read.

Parameters

size	If present and non-negative, specifies the maximum number of bytes to read.

Returns

A list containing the read lines.

xreadlines()

GZipIStream CDPL.Util.GZipIStream.xreadlines

(

)

Returns the stream instance.

Returns

self.

read()

str CDPL.Util.GZipIStream.read

(

int

size = -1

)

Reads at most size bytes.

If the size argument is negative or omitted, all data until EOF is reached are read. The bytes are returned as a string object. An empty string is returned when EOF is encountered immediately.

Parameters

size	If present and non-negative, specifies the maximum number of bytes to read.

Returns

A string containing the read data.

tell()

int CDPL.Util.GZipIStream.tell

(

)

Returns the current read position.

Returns

The current read position.

tellr()

int CDPL.Util.GZipIStream.tellr

(

)

Returns the current read position.

Returns

The current read position.

seek()

None CDPL.Util.GZipIStream.seek	(	int	offs,
		int	whence = 0
	)

Sets the current read position.

The whence argument is optional and defaults to 0 (absolute positioning). Other supported values are 1 to seek relative to the current position and 2 for seeking relative to the end of input.

Parameters

offs	The offset to use for the seek operation.
whence	Value specifying how to calculate the final read position.

seekr()

None CDPL.Util.GZipIStream.seekr	(	int	offs,
		int	whence = 0
	)

Sets the current read position.

The whence argument is optional and defaults to 0 (absolute positioning). Other supported values are 1 to seek relative to the current position and 2 for seeking relative to the end of input.

Parameters

offs	The offset to use for the seek operation.
whence	Value specifying how to calculate the final read position.

next()

str CDPL.Util.GZipIStream.next

(

)

Reads and returns the next line.

A stream object is its own iterator, for example iter(s) returns s. When a stream is used as an iterator, typically in a for loop (for example, for line in s: print line.strip()), the next() method is called repeatedly. This method returns the next input line, or raises StopIteration when EOF is hit when the stream is open for reading (when the stream has been opened for writing only then Base.IOError is raised).

Returns

A string holding the read line.

isClosed()

bool CDPL.Util.GZipIStream.isClosed

(

)

Tells whether the stream has been closed.

See also

close()

getOpenModeString()

str CDPL.Util.GZipIStream.getOpenModeString

(

)

Returns the open mode string that was provided as argument to the constructor.

Returns

The open mode string (e.g. 'r+') that was provided as argument to the constructor.

getOpenModeFlags()

OpenMode CDPL.Util.GZipIStream.getOpenModeFlags

(

)

Returns the open mode flags that were provided as argument to the constructor.

Returns

The open mode flags that were provided as argument to the constructor (see Stream.OpenMode).

close()

None CDPL.Util.GZipIStream.close

(

)

Closes the stream.

A closed stream cannot be read from or written to anymore. Any operation which requires the stream to be open will raise a Base.ValueError after the stream has been closed. Calling close() more than once is allowed.

open()

None CDPL.Util.GZipIStream.open

(

Base.IStream

is

)

Sets the input stream that provides the compressed data.

Parameters

is	The new input stream to read from.

__iter__()

GZipIStream CDPL.Util.GZipIStream.__iter__

(

)

Returns the stream instance.

Returns

self.