diff --git a/Lib/textwrap.py b/Lib/textwrap.py index 4576ef2a3ff..7c68280b38d 100644 --- a/Lib/textwrap.py +++ b/Lib/textwrap.py @@ -161,7 +161,7 @@ class TextWrapper: else: i += 1 - def _handle_long_word(self, chunks, cur_line, cur_len, width): + def _handle_long_word(self, reversed_chunks, cur_line, cur_len, width): """_handle_long_word(chunks : [string], cur_line : [string], cur_len : int, width : int) @@ -174,14 +174,14 @@ class TextWrapper: # If we're allowed to break long words, then do so: put as much # of the next chunk onto the current line as will fit. if self.break_long_words: - cur_line.append(chunks[0][0:space_left]) - chunks[0] = chunks[0][space_left:] + cur_line.append(reversed_chunks[-1][:space_left]) + reversed_chunks[-1] = reversed_chunks[-1][space_left:] # Otherwise, we have to preserve the long word intact. Only add # it to the current line if there's nothing already there -- # that minimizes how much we violate the width constraint. elif not cur_line: - cur_line.append(chunks.pop(0)) + cur_line.append(reversed_chunks.pop()) # If we're not allowed to break long words, and there's already # text on the current line, do nothing. Next time through the @@ -206,6 +206,10 @@ class TextWrapper: if self.width <= 0: raise ValueError("invalid width %r (must be > 0)" % self.width) + # Arrange in reverse order so items can be efficiently popped + # from a stack of chucks. + chunks.reverse() + while chunks: # Start the list of chunks that will make up the current line. @@ -224,15 +228,15 @@ class TextWrapper: # First chunk on line is whitespace -- drop it, unless this # is the very beginning of the text (ie. no lines started yet). - if chunks[0].strip() == '' and lines: - del chunks[0] + if chunks[-1].strip() == '' and lines: + del chunks[-1] while chunks: - l = len(chunks[0]) + l = len(chunks[-1]) # Can at least squeeze this chunk onto the current line. if cur_len + l <= width: - cur_line.append(chunks.pop(0)) + cur_line.append(chunks.pop()) cur_len += l # Nope, this line is full. @@ -241,7 +245,7 @@ class TextWrapper: # The current line is full, and the next chunk is too big to # fit on *any* line (not just this one). - if chunks and len(chunks[0]) > width: + if chunks and len(chunks[-1]) > width: self._handle_long_word(chunks, cur_line, cur_len, width) # If the last chunk on this line is all whitespace, drop it. diff --git a/Misc/NEWS b/Misc/NEWS index 219586fb535..2c0207f0440 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -168,6 +168,9 @@ Extension Modules Library ------- +- textwrap now processes text chucks at O(n) speed instead of O(n**2). + Patch #1209527 (Contributed by Connelly). + - urllib2 has now an attribute 'httpresponses' mapping from HTTP status code to W3C name (404 -> 'Not Found'). RFE #1216944.