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Replaced the last attempt at an "unreadline" with one that actually 

works on non-seekable file-like objects, such as URLs.  (Oops.)
This commit is contained in:
Greg Ward 1999-03-29 18:01:49 +00:00
parent 8e702d4e8e
commit 91c488c1fc
1 changed files with 18 additions and 29 deletions
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47
Lib/distutils/text_file.py
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@ -53,10 +53,10 @@ class TextFile:
self.file = file
self.current_line = 0 # assuming that file is at BOF!
# 'linestart' stores the file offset of the start of each logical
# line; it is used to back up the file pointer when the caller
# wants to "unread" a line
self.linestart = []
# 'linebuf' is a stack of lines that will be emptied before we
# actually read from the file; it's only populated by an
# 'unreadline()' operation
self.linebuf = []
def open (self, filename):
@ -83,14 +83,18 @@ class TextFile:
def readline (self):
# If any "unread" lines waiting in 'linebuf', return the top
# one. (We don't actually buffer read-ahead data -- lines only
# get put in 'linebuf' if the client explicitly does an
# 'unreadline()'.
if self.linebuf:
line = self.linebuf[-1]
del self.linebuf[-1]
return line
buildup_line = ''
while 1:
# record current file position; this will be appended to
# the linestart array *unless* we're accumulating a
# continued logical line
current_pos = self.file.tell()
# read the line, optionally strip comments
line = self.file.readline()
if self.strip_comments and line:
@ -111,11 +115,6 @@ class TextFile:
self.current_line[1] = self.current_line[1] + 1
else:
self.current_line = [self.current_line, self.current_line+1]
# Forget current position: don't want to save it in the
# middle of a logical line
current_pos = None
# just an ordinary line, read it as usual
else:
if not line:
@ -126,7 +125,7 @@ class TextFile:
self.current_line = self.current_line[1] + 1
else:
self.current_line = self.current_line + 1
# strip whitespace however the client wants (leading and
# trailing, or one or the other, or neither)
@ -143,12 +142,6 @@ class TextFile:
if line == '' or line == '\n' and self.skip_blanks:
continue
# if we're still here and have kept the current position,
# then this physical line starts a logical line; record its
# starting offset
if current_pos is not None:
self.linestart.append (current_pos)
if self.join_lines:
if line[-1] == '\\':
buildup_line = line[:-1]
@ -168,14 +161,6 @@ class TextFile:
# end readline
def unreadline (self):
if not self.linestart:
raise IOError, "at beginning of file -- can't unreadline"
pos = self.linestart[-1]
del self.linestart[-1]
self.file.seek (pos)
def readlines (self):
lines = []
while 1:
@ -185,6 +170,10 @@ class TextFile:
lines.append (line)
def unreadline (self, line):
self.linebuf.append (line)
if __name__ == "__main__":
test_data = """# test file