Indent Python code, giving block-closing comments，,'''PYTHON SO

Indent Python code, giving block-closing comments，,'''PYTHON SO

'''PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2--------------------------------------------1. This LICENSE AGREEMENT is between the Python Software Foundation('PSF'), and the Individual or Organization ('Licensee') accessing andotherwise using this software ('Python') in source or binary form andits associated documentation.2. Subject to the terms and conditions of this License Agreement, PSFhereby grants Licensee a nonexclusive, royalty-free, world-widelicense to reproduce, analyze, test, perform and/or display publicly,prepare derivative works, distribute, and otherwise use Pythonalone or in any derivative version, provided, however, that PSF'sLicense Agreement and PSF's notice of copyright, i.e., 'Copyright (c)2001, 2002, 2003, 2004 Python Software Foundation; All Rights Reserved'are retained in Python alone or in any derivative version preparedby Licensee.3. In the event Licensee prepares a derivative work that is based onor incorporates Python or any part thereof, and wants to makethe derivative work available to others as provided herein, thenLicensee hereby agrees to include in any such work a brief summary ofthe changes made to Python.4. PSF is making Python available to Licensee on an 'AS IS'basis.  PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS ORIMPLIED.  BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO ANDDISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESSFOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOTINFRINGE ANY THIRD PARTY RIGHTS.5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHONFOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS ASA RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.6. This License Agreement will automatically terminate upon a materialbreach of its terms and conditions.7. Nothing in this License Agreement shall be deemed to create anyrelationship of agency, partnership, or joint venture between PSF andLicensee.  This License Agreement does not grant permission to use PSFtrademarks or trade name in a trademark sense to endorse or promoteproducts or services of Licensee, or any third party.8. By copying, installing or otherwise using Python, Licenseeagrees to be bound by the terms and conditions of this LicenseAgreement.'''#! /usr/bin/env python# This file contains a class and a main program that perform three# related (though complimentary) formatting operations on Python# programs.  When called as 'pindent -c', it takes a valid Python# program as input and outputs a version augmented with block-closing# comments.  When called as 'pindent -d', it assumes its input is a# Python program with block-closing comments and outputs a commentless# version.   When called as 'pindent -r' it assumes its input is a# Python program with block-closing comments but with its indentation# messed up, and outputs a properly indented version.# A 'block-closing comment' is a comment of the form '# end <keyword>'# where <keyword> is the keyword that opened the block.  If the# opening keyword is 'def' or 'class', the function or class name may# be repeated in the block-closing comment as well.  Here is an# example of a program fully augmented with block-closing comments:# def foobar(a, b):#    if a == b:#        a = a+1#    elif a < b:#        b = b-1#        if b > a: a = a-1#        # end if#    else:#        print 'oops!'#    # end if# # end def foobar# Note that only the last part of an if...elif...else... block needs a# block-closing comment; the same is true for other compound# statements (e.g. try...except).  Also note that 'short-form' blocks# like the second 'if' in the example must be closed as well;# otherwise the 'else' in the example would be ambiguous (remember# that indentation is not significant when interpreting block-closing# comments).# The operations are idempotent (i.e. applied to their own output# they yield an identical result).  Running first 'pindent -c' and# then 'pindent -r' on a valid Python program produces a program that# is semantically identical to the input (though its indentation may# be different). Running 'pindent -e' on that output produces a# program that only differs from the original in indentation.# Other options:# -s stepsize: set the indentation step size (default 8)# -t tabsize : set the number of spaces a tab character is worth (default 8)# -e         : expand TABs into spaces# file ...   : input file(s) (default standard input)# The results always go to standard output# Caveats:# - comments ending in a backslash will be mistaken for continued lines# - continuations using backslash are always left unchanged# - continuations inside parentheses are not extra indented by -r#   but must be indented for -c to work correctly (this breaks#   idempotency!)# - continued lines inside triple-quoted strings are totally garbled# Secret feature:# - On input, a block may also be closed with an 'end statement' --#   this is a block-closing comment without the '#' sign.# Possible improvements:# - check syntax based on transitions in 'next' table# - better error reporting# - better error recovery# - check identifier after class/def# The following wishes need a more complete tokenization of the source:# - Don't get fooled by comments ending in backslash# - reindent continuation lines indicated by backslash# - handle continuation lines inside parentheses/braces/brackets# - handle triple quoted strings spanning lines# - realign comments# - optionally do much more thorough reformatting, a la C indent# DefaultsSTEPSIZE = 8TABSIZE = 8EXPANDTABS = 0import osimport reimport sysnext = {}next['if'] = next['elif'] = 'elif', 'else', 'end'next['while'] = next['for'] = 'else', 'end'next['try'] = 'except', 'finally'next['except'] = 'except', 'else', 'end'next['else'] = next['finally'] = next['def'] = next['class'] = 'end'next['end'] = ()start = 'if', 'while', 'for', 'try', 'def', 'class'class PythonIndenter:    def __init__(self, fpi = sys.stdin, fpo = sys.stdout,                 indentsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):        self.fpi = fpi        self.fpo = fpo        self.indentsize = indentsize        self.tabsize = tabsize        self.lineno = 0        self.expandtabs = expandtabs        self._write = fpo.write        self.kwprog = re.compile(                r'^\s*(?P<kw>[a-z]+)'                r'(\s+(?P<id>[a-zA-Z_]\w*))?'                r'[^\w]')        self.endprog = re.compile(                r'^\s*#?\s*end\s+(?P<kw>[a-z]+)'                r'(\s+(?P<id>[a-zA-Z_]\w*))?'                r'[^\w]')        self.wsprog = re.compile(r'^[ \t]*')    # end def __init__    def write(self, line):        if self.expandtabs:            self._write(line.expandtabs(self.tabsize))        else:            self._write(line)        # end if    # end def write    def readline(self):        line = self.fpi.readline()        if line: self.lineno = self.lineno + 1        # end if        return line    # end def readline    def error(self, fmt, *args):        if args: fmt = fmt % args        # end if        sys.stderr.write('Error at line %d: %s\n' % (self.lineno, fmt))        self.write('### %s ###\n' % fmt)    # end def error    def getline(self):        line = self.readline()        while line[-2:] == '\\\n':            line2 = self.readline()            if not line2: break            # end if            line = line + line2        # end while        return line    # end def getline    def putline(self, line, indent = None):        if indent is None:            self.write(line)            return        # end if        tabs, spaces = divmod(indent*self.indentsize, self.tabsize)        i = 0        m = self.wsprog.match(line)        if m: i = m.end()        # end if        self.write('\t'*tabs + ' '*spaces + line[i:])    # end def putline    def reformat(self):        stack = []        while 1:            line = self.getline()            if not line: break      # EOF            # end if            m = self.endprog.match(line)            if m:                kw = 'end'                kw2 = m.group('kw')                if not stack:                    self.error('unexpected end')                elif stack[-1][0] != kw2:                    self.error('unmatched end')                # end if                del stack[-1:]                self.putline(line, len(stack))                continue            # end if            m = self.kwprog.match(line)            if m:                kw = m.group('kw')                if kw in start:                    self.putline(line, len(stack))                    stack.append((kw, kw))                    continue                # end if                if next.has_key(kw) and stack:                    self.putline(line, len(stack)-1)                    kwa, kwb = stack[-1]                    stack[-1] = kwa, kw                    continue                # end if            # end if            self.putline(line, len(stack))        # end while        if stack:            self.error('unterminated keywords')            for kwa, kwb in stack:                self.write('\t%s\n' % kwa)            # end for        # end if    # end def reformat    def delete(self):        begin_counter = 0        end_counter = 0        while 1:            line = self.getline()            if not line: break      # EOF            # end if            m = self.endprog.match(line)            if m:                end_counter = end_counter + 1                continue            # end if            m = self.kwprog.match(line)            if m:                kw = m.group('kw')                if kw in start:                    begin_counter = begin_counter + 1                # end if            # end if            self.putline(line)        # end while        if begin_counter - end_counter < 0:            sys.stderr.write('Warning: input contained more end tags than expected\n')        elif begin_counter - end_counter > 0:            sys.stderr.write('Warning: input contained less end tags than expected\n')        # end if    # end def delete    def complete(self):        self.indentsize = 1        stack = []        todo = []        thisid = ''        current, firstkw, lastkw, topid = 0, '', '', ''        while 1:            line = self.getline()            i = 0            m = self.wsprog.match(line)            if m: i = m.end()            # end if            m = self.endprog.match(line)            if m:                thiskw = 'end'                endkw = m.group('kw')                thisid = m.group('id')            else:                m = self.kwprog.match(line)                if m:                    thiskw = m.group('kw')                    if not next.has_key(thiskw):                        thiskw = ''                    # end if                    if thiskw in ('def', 'class'):                        thisid = m.group('id')                    else:                        thisid = ''                    # end if                elif line[i:i+1] in ('\n', '#'):                    todo.append(line)                    continue                else:                    thiskw = ''                # end if            # end if            indent = len(line[:i].expandtabs(self.tabsize))            while indent < current:                if firstkw:                    if topid:                        s = '# end %s %s\n' % (                                firstkw, topid)                    else:                        s = '# end %s\n' % firstkw                    # end if                    self.putline(s, current)                    firstkw = lastkw = ''                # end if                current, firstkw, lastkw, topid = stack[-1]                del stack[-1]            # end while            if indent == current and firstkw:                if thiskw == 'end':                    if endkw != firstkw:                        self.error('mismatched end')                    # end if                    firstkw = lastkw = ''                elif not thiskw or thiskw in start:                    if topid:                        s = '# end %s %s\n' % (                                firstkw, topid)                    else:                        s = '# end %s\n' % firstkw                    # end if                    self.putline(s, current)                    firstkw = lastkw = topid = ''                # end if            # end if            if indent > current:                stack.append((current, firstkw, lastkw, topid))                if thiskw and thiskw not in start:                    # error                    thiskw = ''                # end if                current, firstkw, lastkw, topid = \                         indent, thiskw, thiskw, thisid            # end if            if thiskw:                if thiskw in start:                    firstkw = lastkw = thiskw                    topid = thisid                else:                    lastkw = thiskw                # end if            # end if            for l in todo: self.write(l)            # end for            todo = []            if not line: break            # end if            self.write(line)        # end while    # end def complete# end class PythonIndenter# Simplified user interface# - xxx_filter(input, output): read and write file objects# - xxx_string(s): take and return string object# - xxx_file(filename): process file in place, return true iff changeddef complete_filter(input = sys.stdin, output = sys.stdout,                    stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.complete()# end def complete_filterdef delete_filter(input= sys.stdin, output = sys.stdout,                        stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.delete()# end def delete_filterdef reformat_filter(input = sys.stdin, output = sys.stdout,                    stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.reformat()# end def reformat_filterclass StringReader:    def __init__(self, buf):        self.buf = buf        self.pos = 0        self.len = len(self.buf)    # end def __init__    def read(self, n = 0):        if n <= 0:            n = self.len - self.pos        else:            n = min(n, self.len - self.pos)        # end if        r = self.buf[self.pos : self.pos + n]        self.pos = self.pos + n        return r    # end def read    def readline(self):        i = self.buf.find('\n', self.pos)        return self.read(i + 1 - self.pos)    # end def readline    def readlines(self):        lines = []        line = self.readline()        while line:            lines.append(line)            line = self.readline()        # end while        return lines    # end def readlines    # seek/tell etc. are left as an exercise for the reader# end class StringReaderclass StringWriter:    def __init__(self):        self.buf = ''    # end def __init__    def write(self, s):        self.buf = self.buf + s    # end def write    def getvalue(self):        return self.buf    # end def getvalue# end class StringWriterdef complete_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    input = StringReader(source)    output = StringWriter()    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.complete()    return output.getvalue()# end def complete_stringdef delete_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    input = StringReader(source)    output = StringWriter()    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.delete()    return output.getvalue()# end def delete_stringdef reformat_string(source, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    input = StringReader(source)    output = StringWriter()    pi = PythonIndenter(input, output, stepsize, tabsize, expandtabs)    pi.reformat()    return output.getvalue()# end def reformat_stringdef complete_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    source = open(filename, 'r').read()    result = complete_string(source, stepsize, tabsize, expandtabs)    if source == result: return 0    # end if    import os    try: os.rename(filename, filename + '~')    except os.error: pass    # end try    f = open(filename, 'w')    f.write(result)    f.close()    return 1# end def complete_filedef delete_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    source = open(filename, 'r').read()    result = delete_string(source, stepsize, tabsize, expandtabs)    if source == result: return 0    # end if    import os    try: os.rename(filename, filename + '~')    except os.error: pass    # end try    f = open(filename, 'w')    f.write(result)    f.close()    return 1# end def delete_filedef reformat_file(filename, stepsize = STEPSIZE, tabsize = TABSIZE, expandtabs = EXPANDTABS):    source = open(filename, 'r').read()    result = reformat_string(source, stepsize, tabsize, expandtabs)    if source == result: return 0    # end if    import os    try: os.rename(filename, filename + '~')    except os.error: pass    # end try    f = open(filename, 'w')    f.write(result)    f.close()    return 1# end def reformat_file# Test program when called as a scriptusage = '''usage: pindent (-c|-d|-r) [-s stepsize] [-t tabsize] [-e] [file] ...-c         : complete a correctly indented program (add #end directives)-d         : delete #end directives-r         : reformat a completed program (use #end directives)-s stepsize: indentation step (default %(STEPSIZE)d)-t tabsize : the worth in spaces of a tab (default %(TABSIZE)d)-e         : expand TABs into spaces (defailt OFF)[file] ... : files are changed in place, with backups in file~If no files are specified or a single - is given,the program acts as a filter (reads stdin, writes stdout).''' % vars()def error_both(op1, op2):    sys.stderr.write('Error: You can not specify both '+op1+' and -'+op2[0]+' at the same time\n')    sys.stderr.write(usage)    sys.exit(2)# end def error_bothdef test():    import getopt    try:        opts, args = getopt.getopt(sys.argv[1:], 'cdrs:t:e')    except getopt.error, msg:        sys.stderr.write('Error: %s\n' % msg)        sys.stderr.write(usage)        sys.exit(2)    # end try    action = None    stepsize = STEPSIZE    tabsize = TABSIZE    expandtabs = EXPANDTABS    for o, a in opts:        if o == '-c':            if action: error_both(o, action)            # end if            action = 'complete'        elif o == '-d':            if action: error_both(o, action)            # end if            action = 'delete'        elif o == '-r':            if action: error_both(o, action)            # end if            action = 'reformat'        elif o == '-s':            stepsize = int(a)        elif o == '-t':            tabsize = int(a)        elif o == '-e':            expandtabs = 1        # end if    # end for    if not action:        sys.stderr.write(                'You must specify -c(omplete), -d(elete) or -r(eformat)\n')        sys.stderr.write(usage)        sys.exit(2)    # end if    if not args or args == ['-']:        action = eval(action + '_filter')        action(sys.stdin, sys.stdout, stepsize, tabsize, expandtabs)    else:        action = eval(action + '_file')        for filename in args:            action(filename, stepsize, tabsize, expandtabs)        # end for    # end if# end def testif __name__ == '__main__':    test()# end if