cpython-lru_cache-weakref: Lib/StringIO.py annotate

annotate Lib/StringIO.py @ 25838:8540887bcec6 2.2

Backport of 2.183: Fix memory leak in add_subclass() found by NealN with valgrind.

author	Guido van Rossum <guido@python.org>
date	Fri, 18 Oct 2002 13:42:21 +0000
parents	a0005d26773d
children

rev	line source
11691 e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	1 """File-like objects that read from or write to a string buffer.
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	2
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	3 This implements (nearly) all stdio methods.
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	4
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	5 f = StringIO() # ready for writing
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	6 f = StringIO(buf) # ready for reading
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	7 f.close() # explicitly release resources held
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	8 flag = f.isatty() # always false
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	9 pos = f.tell() # get current position
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	10 f.seek(pos) # set current position
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	11 f.seek(pos, mode) # mode 0: absolute; 1: relative; 2: relative to EOF
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	12 buf = f.read() # read until EOF
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	13 buf = f.read(n) # read up to n bytes
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	14 buf = f.readline() # read until end of line ('\n') or EOF
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	15 list = f.readlines()# list of f.readline() results until EOF
14904 b15fce868e50 Add truncate() method to StringIO objects. Fred Drake <fdrake@acm.org> parents: 14680 diff changeset	16 f.truncate([size]) # truncate file at to at most size (default: current pos)
11691 e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	17 f.write(buf) # write at current position
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	18 f.writelines(list) # for line in list: f.write(line)
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	19 f.getvalue() # return whole file's contents as a string
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	20
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	21 Notes:
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	22 - Using a real file is often faster (but less convenient).
11870 d7eca5b0960a Simple changes by Gerrit Holl - move author acknowledgements out of Guido van Rossum <guido@python.org> parents: 11691 diff changeset	23 - There's also a much faster implementation in C, called cStringIO, but
d7eca5b0960a Simple changes by Gerrit Holl - move author acknowledgements out of Guido van Rossum <guido@python.org> parents: 11691 diff changeset	24 it's not subclassable.
11691 e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	25 - fileno() is left unimplemented so that code which uses it triggers
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	26 an exception early.
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	27 - Seeking far beyond EOF and then writing will insert real null
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	28 bytes that occupy space in the buffer.
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	29 - There's a simple test set (see end of this file).
e34991022571 Mass patch by Ka-Ping Yee: Guido van Rossum <guido@python.org> parents: 9016 diff changeset	30 """
21820 a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	31 import types
15541 58bc99e012a8 Accept Finn Bock's patch #102208 to hardcode EINVAL to 22 when errno Barry Warsaw <barry@python.org> parents: 15174 diff changeset	32 try:
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	33 from errno import EINVAL
15541 58bc99e012a8 Accept Finn Bock's patch #102208 to hardcode EINVAL to 22 when errno Barry Warsaw <barry@python.org> parents: 15174 diff changeset	34 except ImportError:
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	35 EINVAL = 22
15541 58bc99e012a8 Accept Finn Bock's patch #102208 to hardcode EINVAL to 22 when errno Barry Warsaw <barry@python.org> parents: 15174 diff changeset	36
16070 b5345e99596b added __all__ lists to a number of Python modules Skip Montanaro <skip@pobox.com> parents: 15555 diff changeset	37 __all__ = ["StringIO"]
b5345e99596b added __all__ lists to a number of Python modules Skip Montanaro <skip@pobox.com> parents: 15555 diff changeset	38
1680 0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	39 class StringIO:
25622 a0005d26773d Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23456 diff changeset	40 """class StringIO([buffer])
a0005d26773d Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23456 diff changeset	41
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	42 When a StringIO object is created, it can be initialized to an existing
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	43 string by passing the string to the constructor. If no string is given,
25622 a0005d26773d Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23456 diff changeset	44 the StringIO will start empty.
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	45
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	46 The StringIO object can accept either Unicode or 8-bit strings, but
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	47 mixing the two may take some care. If both are used, 8-bit strings that
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	48 cannot be interpreted as 7-bit ASCII (that use the 8th bit) will cause
25622 a0005d26773d Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23456 diff changeset	49 a UnicodeError to be raised when getvalue() is called.
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	50 """
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	51 def __init__(self, buf = ''):
21820 a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	52 # Force self.buf to be a string or unicode
22382 165e20ac0ab1 Make StringIO work in non-unicode builds. Michael W. Hudson <mwh@python.net> parents: 21820 diff changeset	53 if type(buf) not in types.StringTypes:
21820 a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	54 buf = str(buf)
a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	55 self.buf = buf
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	56 self.len = len(buf)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	57 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	58 self.pos = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	59 self.closed = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	60 self.softspace = 0
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	61
20032 5c9a955ef17c __iter__(): New method so that StringIO's can participate in the Barry Warsaw <barry@python.org> parents: 16522 diff changeset	62 def __iter__(self):
5c9a955ef17c __iter__(): New method so that StringIO's can participate in the Barry Warsaw <barry@python.org> parents: 16522 diff changeset	63 return iter(self.readline, '')
5c9a955ef17c __iter__(): New method so that StringIO's can participate in the Barry Warsaw <barry@python.org> parents: 16522 diff changeset	64
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	65 def close(self):
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	66 """Free the memory buffer."""
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	67 if not self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	68 self.closed = 1
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	69 del self.buf, self.pos
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	70
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	71 def isatty(self):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	72 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	73 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	74 return 0
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	75
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	76 def seek(self, pos, mode = 0):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	77 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	78 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	79 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	80 self.buf += ''.join(self.buflist)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	81 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	82 if mode == 1:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	83 pos += self.pos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	84 elif mode == 2:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	85 pos += self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	86 self.pos = max(0, pos)
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	87
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	88 def tell(self):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	89 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	90 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	91 return self.pos
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	92
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	93 def read(self, n = -1):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	94 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	95 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	96 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	97 self.buf += ''.join(self.buflist)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	98 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	99 if n < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	100 newpos = self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	101 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	102 newpos = min(self.pos+n, self.len)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	103 r = self.buf[self.pos:newpos]
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	104 self.pos = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	105 return r
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	106
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	107 def readline(self, length=None):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	108 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	109 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	110 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	111 self.buf += ''.join(self.buflist)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	112 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	113 i = self.buf.find('\n', self.pos)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	114 if i < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	115 newpos = self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	116 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	117 newpos = i+1
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	118 if length is not None:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	119 if self.pos + length < newpos:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	120 newpos = self.pos + length
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	121 r = self.buf[self.pos:newpos]
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	122 self.pos = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	123 return r
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	124
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	125 def readlines(self, sizehint = 0):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	126 total = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	127 lines = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	128 line = self.readline()
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	129 while line:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	130 lines.append(line)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	131 total += len(line)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	132 if 0 < sizehint <= total:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	133 break
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	134 line = self.readline()
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	135 return lines
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	136
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	137 def truncate(self, size=None):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	138 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	139 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	140 if size is None:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	141 size = self.pos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	142 elif size < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	143 raise IOError(EINVAL, "Negative size not allowed")
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	144 elif size < self.pos:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	145 self.pos = size
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	146 self.buf = self.getvalue()[:size]
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	147
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	148 def write(self, s):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	149 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	150 raise ValueError, "I/O operation on closed file"
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	151 if not s: return
21820 a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	152 # Force s to be a string or unicode
22382 165e20ac0ab1 Make StringIO work in non-unicode builds. Michael W. Hudson <mwh@python.net> parents: 21820 diff changeset	153 if type(s) not in types.StringTypes:
21820 a4e4736799b1 It's merge time! Michael W. Hudson <mwh@python.net> parents: 20060 diff changeset	154 s = str(s)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	155 if self.pos > self.len:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	156 self.buflist.append('\0'*(self.pos - self.len))
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	157 self.len = self.pos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	158 newpos = self.pos + len(s)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	159 if self.pos < self.len:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	160 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	161 self.buf += ''.join(self.buflist)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	162 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	163 self.buflist = [self.buf[:self.pos], s, self.buf[newpos:]]
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	164 self.buf = ''
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	165 if newpos > self.len:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	166 self.len = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	167 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	168 self.buflist.append(s)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	169 self.len = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	170 self.pos = newpos
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	171
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	172 def writelines(self, list):
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	173 self.write(''.join(list))
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	174
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	175 def flush(self):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	176 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	177 raise ValueError, "I/O operation on closed file"
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	178
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	179 def getvalue(self):
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	180 """
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	181 Retrieve the entire contents of the "file" at any time before
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	182 the StringIO object's close() method is called.
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	183
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	184 The StringIO object can accept either Unicode or 8-bit strings,
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	185 but mixing the two may take some care. If both are used, 8-bit
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	186 strings that cannot be interpreted as 7-bit ASCII (that use the
64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	187 8th bit) will cause a UnicodeError to be raised when getvalue()
25622 a0005d26773d Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23456 diff changeset	188 is called.
23456 64eb119b816d Add docstrings excerpted from the library reference. Raymond Hettinger <python@rcn.com> parents: 22382 diff changeset	189 """
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	190 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	191 self.buf += ''.join(self.buflist)
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	192 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	193 return self.buf
1680 0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	194
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	195
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	196 # A little test suite
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	197
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	198 def test():
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	199 import sys
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	200 if sys.argv[1:]:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	201 file = sys.argv[1]
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	202 else:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	203 file = '/etc/passwd'
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	204 lines = open(file, 'r').readlines()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	205 text = open(file, 'r').read()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	206 f = StringIO()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	207 for line in lines[:-2]:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	208 f.write(line)
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	209 f.writelines(lines[-2:])
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	210 if f.getvalue() != text:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	211 raise RuntimeError, 'write failed'
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	212 length = f.tell()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	213 print 'File length =', length
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	214 f.seek(len(lines[0]))
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	215 f.write(lines[1])
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	216 f.seek(0)
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	217 print 'First line =', `f.readline()`
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	218 here = f.tell()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	219 line = f.readline()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	220 print 'Second line =', `line`
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	221 f.seek(-len(line), 1)
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	222 line2 = f.read(len(line))
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	223 if line != line2:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	224 raise RuntimeError, 'bad result after seek back'
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	225 f.seek(len(line2), 1)
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	226 list = f.readlines()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	227 line = list[-1]
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	228 f.seek(f.tell() - len(line))
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	229 line2 = f.read()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	230 if line != line2:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	231 raise RuntimeError, 'bad result after seek back from EOF'
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	232 print 'Read', len(list), 'more lines'
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	233 print 'File length =', f.tell()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	234 if f.tell() != length:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	235 raise RuntimeError, 'bad length'
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	236 f.close()
1680 0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	237
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	238 if __name__ == '__main__':
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	239 test()

Mercurial > cpython-lru_cache-weakref

annotate Lib/StringIO.py @ 25838:8540887bcec6 2.2