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

annotate Lib/StringIO.py @ 19283:b865cd5c1925 legacy-trunk

Added comments before recently added/assigned slots in the type object, so the backward compatibility issues will be easier to understand. I only added comments indicating additions and assignments back to Python 2.0.

author	Fred Drake <fdrake@acm.org>
date	Wed, 15 Aug 2001 18:32:33 +0000
parents	f42799c68929
children	5c9a955ef17c

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 """
1680 0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	31
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:
15542 6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	40 def __init__(self, buf = ''):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	41 self.buf = buf
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	42 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	43 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	44 self.pos = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	45 self.closed = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	46 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	47
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	48 def close(self):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	49 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	50 self.closed = 1
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	51 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	52
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	53 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	54 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	55 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	56 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	57
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	58 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	59 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	60 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	61 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	62 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	63 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	64 if mode == 1:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	65 pos += self.pos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	66 elif mode == 2:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	67 pos += self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	68 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	69
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	70 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	71 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	72 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	73 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	74
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	75 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	76 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	77 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	78 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	79 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	80 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	81 if n < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	82 newpos = self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	83 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	84 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	85 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	86 self.pos = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	87 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	88
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	89 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	90 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	91 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	92 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	93 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	94 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	95 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	96 if i < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	97 newpos = self.len
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	98 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	99 newpos = i+1
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	100 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	101 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	102 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	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 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	108 total = 0
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	109 lines = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	110 line = self.readline()
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	111 while line:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	112 lines.append(line)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	113 total += len(line)
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	114 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	115 break
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	116 line = self.readline()
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	117 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	118
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	119 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	120 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	121 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	122 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	123 size = self.pos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	124 elif size < 0:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	125 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	126 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	127 self.pos = size
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	128 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	129
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	130 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	131 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	132 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	133 if not s: return
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	134 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	135 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	136 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	137 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	138 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	139 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	140 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	141 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	142 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	143 self.buf = ''
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	144 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	145 self.len = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	146 else:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	147 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	148 self.len = newpos
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	149 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	150
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	151 def writelines(self, list):
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	152 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	153
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	154 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	155 if self.closed:
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	156 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	157
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	158 def getvalue(self):
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	159 if self.buflist:
16522 f42799c68929 Remove silly EMPTYSTRING global. Saves a global lookup. Marc-André Lemburg <mal@egenix.com> parents: 16070 diff changeset	160 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	161 self.buflist = []
f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	162 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	163
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	164
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	165 # 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	166
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	167 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	168 import sys
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	169 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	170 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	171 else:
15555 f72345b43662 Untabify! (Barry, this is gonna cost you a bottle of wine! ;) Fred Drake <fdrake@acm.org> parents: 15542 diff changeset	172 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	173 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	174 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	175 f = StringIO()
6359480106ec Change the file's indentation from tabs to 4 spaces per level. Barry Warsaw <barry@python.org> parents: 15541 diff changeset	176 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	177 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	178 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	179 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	180 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	181 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	182 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	183 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	184 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	185 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	186 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	187 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	188 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	189 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	190 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	191 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	192 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	193 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	194 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	195 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	196 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	197 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	198 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	199 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	200 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	201 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	202 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	203 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	204 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	205 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	206
0a60460e99f0 Two new generally useful modules: types defines names for all built-in types, Guido van Rossum <guido@python.org> parents: diff changeset	207 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	208 test()

Mercurial > cpython-lru_cache-weakref

annotate Lib/StringIO.py @ 19283:b865cd5c1925 legacy-trunk