CDPL.Base.FileIOStream Class Reference

Wrapper for C++ std::fstream exposing a Python-style file-oriented I/O interface. More...

Inheritance diagram for CDPL.Base.FileIOStream:

Public Member Functions
None	__init__ (str file_name, str mode='r')
	Constructs the FileIOStream instance and opens the specified file in the given mode. More...
None	__init__ (str file_name, OpenMode mode=IOStream.OpenMode.IN)
	Constructs the FileIOStream instance and opens the specified file in the given mode. 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...
FileIOStream	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	flush ()
	Flushes the internal buffer.
None	write (object string)
	Outputs the specified string. More...
None	writelines (object iterable)
	Outputs the specified sequence of strings. More...
int	tellw ()
	Returns the current write position. More...
None	seekw (int offs, int whence=0)
	Sets the current write position. More...
bool	getSoftSpace ()
	Returns a boolean that indicates whether a space character needs to be printed before another value when using the print statement. More...
None	setSoftSpace (bool value)
	Sets a boolean that indicates whether a space character needs to be printed before another value when using the print statement. More...
None	close ()
	Closes the stream. More...
str	getFileName ()
	Return the file path string that got passed to the constructor. More...
FileIOStream	__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...
Public Member Functions inherited from CDPL.Base.OStream
int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...

Properties
	closed = property(isClosed)
	mode = property(getOpenModeString)
	modeFlags = property(getOpenModeFlags)
	softspace = property(getSoftSpace, setSoftSpace)
	name = property(getFileName)
Properties inherited from CDPL.Base.IStream
	objectID = property(getObjectID)
Properties inherited from CDPL.Base.OStream
	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.
Static Public Attributes inherited from CDPL.Base.OStream
	STD_OUT = _HIDDEN_VALUE_
	The standard output stream of the current process.
	STD_ERR = _HIDDEN_VALUE_
	The standard error stream of the current process.

Detailed Description

Wrapper for C++ std::fstream exposing a Python-style file-oriented I/O interface.

Constructor & Destructor Documentation

__init__() [1/2]

None CDPL.Base.FileIOStream.__init__	(	str	file_name,
		str	mode = 'r'
	)

Constructs the FileIOStream instance and opens the specified file in the given mode.

Parameters

file_name	The path to the file to open.
mode	A combination of file open mode flags (see IOStream.OpenMode) or a Python-style open mode string (e.g. 'r+').

__init__() [2/2]

None CDPL.Base.FileIOStream.__init__	(	str	file_name,
		OpenMode	mode = IOStream.OpenMode.IN
	)

Constructs the FileIOStream instance and opens the specified file in the given mode.

Parameters

file_name	The path to the file to open.
mode	A combination of file open mode flags (see IOStream.OpenMode) or a Python-style open mode string (e.g. 'r+').

Member Function Documentation

readline()

str CDPL.Base.FileIOStream.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.Base.FileIOStream.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()

FileIOStream CDPL.Base.FileIOStream.xreadlines

(

)

Returns the stream instance.

Returns

self.

read()

str CDPL.Base.FileIOStream.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.Base.FileIOStream.tell

(

)

Returns the current read position.

Returns

The current read position.

tellr()

int CDPL.Base.FileIOStream.tellr

(

)

Returns the current read position.

Returns

The current read position.

seek()

None CDPL.Base.FileIOStream.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.Base.FileIOStream.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.Base.FileIOStream.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.Base.FileIOStream.isClosed

(

)

Tells whether the stream has been closed.

See also

close()

getOpenModeString()

str CDPL.Base.FileIOStream.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.Base.FileIOStream.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).

write()

None CDPL.Base.FileIOStream.write

(

object

string

)

Outputs the specified string.

Parameters

string

The string to output.

Note

Due to buffering, the string may not actually show up in the file until the flush() or close() method is called.

writelines()

None CDPL.Base.FileIOStream.writelines

(

object

iterable

)

Outputs the specified sequence of strings.

Parameters

iterable

The string sequence to output (can be any iterable object producing strings, typically a list of strings).

tellw()

int CDPL.Base.FileIOStream.tellw

(

)

Returns the current write position.

Returns

The current write position.

seekw()

None CDPL.Base.FileIOStream.seekw	(	int	offs,
		int	whence = 0
	)

Sets the current write 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 write position.

getSoftSpace()

bool CDPL.Base.FileIOStream.getSoftSpace

(

)

Returns a boolean that indicates whether a space character needs to be printed before another value when using the print statement.

Returns

True if a space character needs to be printed before another value when using the print statement, and False otherwise.

setSoftSpace()

None CDPL.Base.FileIOStream.setSoftSpace

(

bool

value

)

Sets a boolean that indicates whether a space character needs to be printed before another value when using the print statement.

Parameters

value

True if a space character shall be printed before another value when using the print statement, and False otherwise.

close()

None CDPL.Base.FileIOStream.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.

getFileName()

str CDPL.Base.FileIOStream.getFileName

(

)

Return the file path string that got passed to the constructor.

Returns

The file path string that got passed to the constructor.

__iter__()

FileIOStream CDPL.Base.FileIOStream.__iter__

(

)

Returns the stream instance.

Returns

self.