Make 'width' an instance attribute rather than an argument to the wrap()

and fill() methods.  Keep interface of existing wrap() and fill()
functions by going back to having them construct a new TextWrapper
instance on each call, with the preferred width passed to the
constructor.

Lib/textwrap.py

@@ -18,8 +18,10 @@ class TextWrapper:
     If you want to completely replace the main wrapping algorithm,
     you'll probably have to override _wrap_chunks().
 
-    Several boolean instance attributes control various aspects of
-    wrapping:
+    Several instance attributes control various aspects of wrapping:
+      width (default: 70)
+        the maximum width of wrapped lines (unless break_long_words
+        is false)
       expand_tabs (default: true)
         Expand tabs in input text to spaces before further processing.
         Each tab will become 1 .. 8 spaces, depending on its position in
@@ -34,9 +36,8 @@ class TextWrapper:
         by two spaces.  Off by default becaus the algorithm is
         (unavoidably) imperfect.
       break_long_words (default: true)
-        Break words longer than the line width constraint.  If false,
-        those words will not be broken, and some lines might be longer
-        than the width constraint.
+        Break words longer than 'width'.  If false, those words will not
+        be broken, and some lines might be longer than 'width'.
     """
 
     whitespace_trans = string.maketrans(string.whitespace,
@@ -61,10 +62,12 @@ class TextWrapper:
 
 
     def __init__ (self,
+                  width=70,
                   expand_tabs=True,
                   replace_whitespace=True,
                   fix_sentence_endings=False,
                   break_long_words=True):
+        self.width = width
         self.expand_tabs = expand_tabs
         self.replace_whitespace = replace_whitespace
         self.fix_sentence_endings = fix_sentence_endings
@@ -121,15 +124,15 @@ class TextWrapper:
             else:
                 i += 1
 
-    def _handle_long_word(self, chunks, cur_line, cur_len, width):
+    def _handle_long_word(self, chunks, cur_line, cur_len):
         """_handle_long_word(chunks : [string],
                              cur_line : [string],
-                             cur_len : int, width : int)
+                             cur_len : int)
 
         Handle a chunk of text (most likely a word, not whitespace) that
         is too long to fit in any line.
         """
-        space_left = width - cur_len
+        space_left = self.width - cur_len
 
         # 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.
@@ -149,20 +152,21 @@ class TextWrapper:
         # cur_len will be zero, so the next line will be entirely
         # devoted to the long word that we can't handle right now.
 
-    def _wrap_chunks(self, chunks, width):
-        """_wrap_chunks(chunks : [string], width : int) -> [string]
+    def _wrap_chunks(self, chunks):
+        """_wrap_chunks(chunks : [string]) -> [string]
 
         Wrap a sequence of text chunks and return a list of lines of
-        length 'width' or less.  (If 'break_long_words' is false, some
-        lines may be longer than 'width'.)  Chunks correspond roughly to
-        words and the whitespace between them: each chunk is indivisible
-        (modulo 'break_long_words'), but a line break can come between
-        any two chunks.  Chunks should not have internal whitespace;
-        ie. a chunk is either all whitespace or a "word".  Whitespace
-        chunks will be removed from the beginning and end of lines, but
-        apart from that whitespace is preserved.
+        length 'self.width' or less.  (If 'break_long_words' is false,
+        some lines may be longer than this.)  Chunks correspond roughly
+        to words and the whitespace between them: each chunk is
+        indivisible (modulo 'break_long_words'), but a line break can
+        come between any two chunks.  Chunks should not have internal
+        whitespace; ie. a chunk is either all whitespace or a "word".
+        Whitespace chunks will be removed from the beginning and end of
+        lines, but apart from that whitespace is preserved.
         """
         lines = []
+        width = self.width
 
         while chunks:
 
@@ -188,7 +192,7 @@ 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:
-                self._handle_long_word(chunks, cur_line, cur_len, width)
+                self._handle_long_word(chunks, cur_line, cur_len)
 
             # If the last chunk on this line is all whitespace, drop it.
             if cur_line and cur_line[-1].strip() == '':
@@ -204,26 +208,25 @@ class TextWrapper:
 
     # -- Public interface ----------------------------------------------
 
-    def wrap(self, text, width):
-        """wrap(text : string, width : int) -> [string]
+    def wrap(self, text):
+        """wrap(text : string) -> [string]
 
-        Split 'text' into multiple lines of no more than 'width'
+        Split 'text' into multiple lines of no more than 'self.width'
         characters each, and return the list of strings that results.
         Tabs in 'text' are expanded with string.expandtabs(), and all
         other whitespace characters (including newline) are converted to
         space.
         """
         text = self._munge_whitespace(text)
-        if len(text) <= width:
+        if len(text) <= self.width:
             return [text]
         chunks = self._split(text)
         if self.fix_sentence_endings:
             self._fix_sentence_endings(chunks)
-        return self._wrap_chunks(chunks, width)
+        return self._wrap_chunks(chunks)
 
-    def fill(self, text, width, initial_tab="", subsequent_tab=""):
+    def fill(self, text, initial_tab="", subsequent_tab=""):
         """fill(text : string,
-                width : int,
                 initial_tab : string = "",
                 subsequent_tab : string = "")
            -> string
@@ -234,17 +237,15 @@ class TextWrapper:
         lengths of the tab strings are accounted for when wrapping lines
         to fit in 'width' columns.
         """
-        lines = self.wrap(text, width)
+        lines = self.wrap(text)
         sep = "\n" + subsequent_tab
         return initial_tab + sep.join(lines)
 
 
 # Convenience interface
 
-_wrapper = TextWrapper()
-
 def wrap(text, width):
-    return _wrapper.wrap(text, width)
+    return TextWrapper(width=width).wrap(text)
 
 def fill(text, width, initial_tab="", subsequent_tab=""):
-    return _wrapper.fill(text, width, initial_tab, subsequent_tab)
+    return TextWrapper(width=width).fill(text, initial_tab, subsequent_tab)