Edit file File name : StringIO.pyc Content :� �bc @ s| d Z y d d l m Z Wn e k r3 d Z n Xd g Z d � Z d d d � � YZ d � Z e d k rx e � n d S( s File-like objects that read from or write to a string buffer. This implements (nearly) all stdio methods. f = StringIO() # ready for writing f = StringIO(buf) # ready for reading f.close() # explicitly release resources held flag = f.isatty() # always false pos = f.tell() # get current position f.seek(pos) # set current position f.seek(pos, mode) # mode 0: absolute; 1: relative; 2: relative to EOF buf = f.read() # read until EOF buf = f.read(n) # read up to n bytes buf = f.readline() # read until end of line ('\n') or EOF list = f.readlines()# list of f.readline() results until EOF f.truncate([size]) # truncate file at to at most size (default: current pos) f.write(buf) # write at current position f.writelines(list) # for line in list: f.write(line) f.getvalue() # return whole file's contents as a string Notes: - Using a real file is often faster (but less convenient). - There's also a much faster implementation in C, called cStringIO, but it's not subclassable. - fileno() is left unimplemented so that code which uses it triggers an exception early. - Seeking far beyond EOF and then writing will insert real null bytes that occupy space in the buffer. - There's a simple test set (see end of this file). i����( t EINVALi t StringIOc C s | r t d � n d S( Ns I/O operation on closed file( t ValueError( t closed( ( s /usr/lib/python2.7/StringIO.pyt _complain_ifclosed& s c B s� e Z d Z d d � Z d � Z d � Z d � Z d � Z d d � Z d � Z d d � Z d d � Z d d � Z d d � Z d � Z d � Z d � Z d � Z RS( s� class StringIO([buffer]) When a StringIO object is created, it can be initialized to an existing string by passing the string to the constructor. If no string is given, the StringIO will start empty. The StringIO object can accept either Unicode or 8-bit strings, but mixing the two may take some care. If both are used, 8-bit strings that cannot be interpreted as 7-bit ASCII (that use the 8th bit) will cause a UnicodeError to be raised when getvalue() is called. t c C s^ t | t � s t | � } n | | _ t | � | _ g | _ d | _ t | _ d | _ d S( Ni ( t isinstancet basestringt strt buft lent buflistt post FalseR t softspace( t selfR ( ( s /usr/lib/python2.7/StringIO.pyt __init__6 s c C s | S( N( ( R ( ( s /usr/lib/python2.7/StringIO.pyt __iter__A s c C s, t | j � | j � } | s( t � n | S( s_ A file object is its own iterator, for example iter(f) returns f (unless f is closed). When a file is used as an iterator, typically in a for loop (for example, for line in f: print line), the next() method is called repeatedly. This method returns the next input line, or raises StopIteration when EOF is hit. ( R R t readlinet StopIteration( R t r( ( s /usr/lib/python2.7/StringIO.pyt nextD s c C s% | j s! t | _ | ` | ` n d S( s Free the memory buffer. N( R t TrueR R ( R ( ( s /usr/lib/python2.7/StringIO.pyt closeQ s c C s t | j � t S( s_ Returns False because StringIO objects are not connected to a tty-like device. ( R R R ( R ( ( s /usr/lib/python2.7/StringIO.pyt isattyX s i c C s� t | j � | j r= | j d j | j � 7_ g | _ n | d k rY | | j 7} n | d k ru | | j 7} n t d | � | _ d S( s Set the file's current position. The mode argument is optional and defaults to 0 (absolute file positioning); other values are 1 (seek relative to the current position) and 2 (seek relative to the file's end). There is no return value. R i i i N( R R R R t joinR R t max( R R t mode( ( s /usr/lib/python2.7/StringIO.pyt seek_ s c C s t | j � | j S( s# Return the file's current position.( R R R ( R ( ( s /usr/lib/python2.7/StringIO.pyt tellr s i����c C s� t | j � | j r= | j d j | j � 7_ g | _ n | d k sU | d k ra | j } n t | j | | j � } | j | j | !} | | _ | S( sE Read at most size bytes from the file (less if the read hits EOF before obtaining size bytes). If the size argument is negative or omitted, read all data until EOF is reached. The bytes are returned as a string object. An empty string is returned when EOF is encountered immediately. R i N( R R R R R t NoneR t minR ( R t nt newposR ( ( s /usr/lib/python2.7/StringIO.pyt readw s c C s� t | j � | j r= | j d j | j � 7_ g | _ n | j j d | j � } | d k rm | j } n | d } | d k r� | d k r� | j | | k r� | j | } q� n | j | j | !} | | _ | S( s% Read one entire line from the file. 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. An empty string is returned only when EOF is encountered immediately. Note: Unlike stdio's fgets(), the returned string contains null characters ('\0') if they occurred in the input. R s i i N( R R R R R t findR R R ( R t lengtht iR! R ( ( s /usr/lib/python2.7/StringIO.pyR � s c C sr d } g } | j � } xS | rm | j | � | t | � 7} d | k oU | k n r^ Pn | j � } q W| S( s' Read until EOF using readline() and return a list containing the lines thus read. If the optional sizehint argument is present, instead of reading up to EOF, whole lines totalling approximately sizehint bytes (or more to accommodate a final whole line). i ( R t appendR ( R t sizehintt totalt linest line( ( s /usr/lib/python2.7/StringIO.pyt readlines� s c C s~ t | j � | d k r% | j } n9 | d k rC t t d � � n | | j k r^ | | _ n | j � | | _ | | _ d S( s� Truncate the file's size. If the optional size argument is present, the file is truncated to (at most) that size. The size defaults to the current position. The current file position is not changed unless the position is beyond the new file size. If the specified size exceeds the file's current size, the file remains unchanged. i s Negative size not allowedN( R R R R t IOErrorR t getvalueR R ( R t size( ( s /usr/lib/python2.7/StringIO.pyt truncate� s c C s^ t | j � | s d St | t � s5 t | � } n | j } | j } | | k r� | j j | � | t | � | _ | _ d S| | k r� | j j d | | � | } n | t | � } | | k r2| j r� | j d j | j � 7_ n | j | | | j | g | _ d | _ | | k rH| } qHn | j j | � | } | | _ | | _ d S( sG Write a string to the file. There is no return value. Ns R ( R R R R R R R R R& R R ( R t st spost slenR! ( ( s /usr/lib/python2.7/StringIO.pyt write� s4 c C s( | j } x | D] } | | � q Wd S( s Write a sequence of strings to the file. The sequence can be any iterable object producing strings, typically a list of strings. There is no return value. (The name is intended to match readlines(); writelines() does not add line separators.) N( R3 ( R t iterableR3 R* ( ( s /usr/lib/python2.7/StringIO.pyt writelines� s c C s t | j � d S( s" Flush the internal buffer N( R R ( R ( ( s /usr/lib/python2.7/StringIO.pyt flush� s c C sD t | j � | j r= | j d j | j � 7_ g | _ n | j S( s� Retrieve the entire contents of the "file" at any time before the StringIO object's close() method is called. The StringIO object can accept either Unicode or 8-bit strings, but mixing the two may take some care. If both are used, 8-bit strings that cannot be interpreted as 7-bit ASCII (that use the 8th bit) will cause a UnicodeError to be raised when getvalue() is called. R ( R R R R R ( R ( ( s /usr/lib/python2.7/StringIO.pyR- s N( t __name__t __module__t __doc__R R R R R R R R" R R R+ R/ R3 R5 R6 R- ( ( ( s /usr/lib/python2.7/StringIO.pyR * s ! c C s� d d l } | j d r) | j d } n d } t | d � j � } t | d � j � } t � } x | d D] } | j | � qm W| j | d � | j � | k r� t d � n | j � } d G| GH| j t | d � � | j | d � | j d � d Gt | j � � GHd G| j � GH| j � } d Gt | � GH| j t | � d � | j t | � � } | | k r�t d � n | j t | � d � | j � } | d } | j | j � t | � � | j � } | | k r�t d � n d Gt | � Gd GHd G| j � GH| j � | k r-t d � n | j | d � | j d d � d G| j � GH| j � | d k rt d � n | j � d S( Ni����i s /etc/passwdR i����s write faileds File length =i s First line =s Position =s Second line =s bad result after seek backs# bad result after seek back from EOFt Reads more liness bad lengthi s Truncated length =s truncate did not adjust length( t syst argvt openR+ R" R R3 R5 R- t RuntimeErrorR R R t reprR R/ R ( R; t fileR) t textt fR* R$ t line2t list( ( s /usr/lib/python2.7/StringIO.pyt test sT t __main__N( ( R9 t errnoR t ImportErrort __all__R R RE R7 ( ( ( s /usr/lib/python2.7/StringIO.pyt <module> s � - Save