Search Python (.py) files for future statements, and remove the features from such statements，.pystatements,'''PYTHON SO

Search Python (.py) files for future statements, and remove the features from such statements，.pystatements,'''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'''cleanfuture [-d][-r][-v] path ...-d  Dry run.  Analyze, but don't make any changes to, files.-r  Recurse.  Search for all .py files in subdirectories too.-v  Verbose.  Print informative msgs.Search Python (.py) files for future statements, and remove the featuresfrom such statements that are already mandatory in the version of Pythonyou're using.Pass one or more file and/or directory paths.  When a directory path, all.py files within the directory will be examined, and, if the -r option isgiven, likewise recursively for subdirectories.Overwrites files in place, renaming the originals with a .bak extension. Ifcleanfuture finds nothing to change, the file is left alone.  If cleanfuturedoes change a file, the changed file is a fixed-point (i.e., runningcleanfuture on the resulting .py file won't change it again, at least notuntil you try it again with a later Python release).Limitations:  You can do these things, but this tool won't help you then:+ A future statement cannot be mixed with any other statement on the same  physical line (separated by semicolon).+ A future statement cannot contain an 'as' clause.Example:  Assuming you're using Python 2.2, if a file containingfrom __future__ import nested_scopes, generatorsis analyzed by cleanfuture, the line is rewritten tofrom __future__ import generatorsbecause nested_scopes is no longer optional in 2.2 but generators is.'''import __future__import tokenizeimport osimport sysdryrun  = 0recurse = 0verbose = 0def errprint(*args):    strings = map(str, args)    msg = ' '.join(strings)    if msg[-1:] != '\n':        msg += '\n'    sys.stderr.write(msg)def main():    import getopt    global verbose, recurse, dryrun    try:        opts, args = getopt.getopt(sys.argv[1:], 'drv')    except getopt.error, msg:        errprint(msg)        return    for o, a in opts:        if o == '-d':            dryrun += 1        elif o == '-r':            recurse += 1        elif o == '-v':            verbose += 1    if not args:        errprint('Usage:', __doc__)        return    for arg in args:        check(arg)def check(file):    if os.path.isdir(file) and not os.path.islink(file):        if verbose:            print 'listing directory', file        names = os.listdir(file)        for name in names:            fullname = os.path.join(file, name)            if ((recurse and os.path.isdir(fullname) and                 not os.path.islink(fullname))                or name.lower().endswith('.py')):                check(fullname)        return    if verbose:        print 'checking', file, '...',    try:        f = open(file)    except IOError, msg:        errprint('%r: I/O Error: %s' % (file, str(msg)))        return    ff = FutureFinder(f, file)    changed = ff.run()    if changed:        ff.gettherest()    f.close()    if changed:        if verbose:            print 'changed.'            if dryrun:                print 'But this is a dry run, so leaving it alone.'        for s, e, line in changed:            print '%r lines %d-%d' % (file, s+1, e+1)            for i in range(s, e+1):                print ff.lines[i],            if line is None:                print '-- deleted'            else:                print '-- change to:'                print line,        if not dryrun:            bak = file + '.bak'            if os.path.exists(bak):                os.remove(bak)            os.rename(file, bak)            if verbose:                print 'renamed', file, 'to', bak            g = open(file, 'w')            ff.write(g)            g.close()            if verbose:                print 'wrote new', file    else:        if verbose:            print 'unchanged.'class FutureFinder:    def __init__(self, f, fname):        self.f = f        self.fname = fname        self.ateof = 0        self.lines = [] # raw file lines        # List of (start_index, end_index, new_line) triples.        self.changed = []    # Line-getter for tokenize.    def getline(self):        if self.ateof:            return ''        line = self.f.readline()        if line == '':            self.ateof = 1        else:            self.lines.append(line)        return line    def run(self):        STRING = tokenize.STRING        NL = tokenize.NL        NEWLINE = tokenize.NEWLINE        COMMENT = tokenize.COMMENT        NAME = tokenize.NAME        OP = tokenize.OP        changed = self.changed        get = tokenize.generate_tokens(self.getline).next        type, token, (srow, scol), (erow, ecol), line = get()        # Chew up initial comments and blank lines (if any).        while type in (COMMENT, NL, NEWLINE):            type, token, (srow, scol), (erow, ecol), line = get()        # Chew up docstring (if any -- and it may be implicitly catenated!).        while type is STRING:            type, token, (srow, scol), (erow, ecol), line = get()        # Analyze the future stmts.        while 1:            # Chew up comments and blank lines (if any).            while type in (COMMENT, NL, NEWLINE):                type, token, (srow, scol), (erow, ecol), line = get()            if not (type is NAME and token == 'from'):                break            startline = srow - 1    # tokenize is one-based            type, token, (srow, scol), (erow, ecol), line = get()            if not (type is NAME and token == '__future__'):                break            type, token, (srow, scol), (erow, ecol), line = get()            if not (type is NAME and token == 'import'):                break            type, token, (srow, scol), (erow, ecol), line = get()            # Get the list of features.            features = []            while type is NAME:                features.append(token)                type, token, (srow, scol), (erow, ecol), line = get()                if not (type is OP and token == ','):                    break                type, token, (srow, scol), (erow, ecol), line = get()            # A trailing comment?            comment = None            if type is COMMENT:                comment = token                type, token, (srow, scol), (erow, ecol), line = get()            if type is not NEWLINE:                errprint('Skipping file %r; can't parse line %d:\n%s' %                         (self.fname, srow, line))                return []            endline = srow - 1            # Check for obsolete features.            okfeatures = []            for f in features:                object = getattr(__future__, f, None)                if object is None:                    # A feature we don't know about yet -- leave it in.                    # They'll get a compile-time error when they compile                    # this program, but that's not our job to sort out.                    okfeatures.append(f)                else:                    released = object.getMandatoryRelease()                    if released is None or released <= sys.version_info:                        # Withdrawn or obsolete.                        pass                    else:                        okfeatures.append(f)            # Rewrite the line if at least one future-feature is obsolete.            if len(okfeatures) < len(features):                if len(okfeatures) == 0:                    line = None                else:                    line = 'from __future__ import '                    line += ', '.join(okfeatures)                    if comment is not None:                        line += ' ' + comment                    line += '\n'                changed.append((startline, endline, line))            # Loop back for more future statements.        return changed    def gettherest(self):        if self.ateof:            self.therest = ''        else:            self.therest = self.f.read()    def write(self, f):        changed = self.changed        assert changed        # Prevent calling this again.        self.changed = []        # Apply changes in reverse order.        changed.reverse()        for s, e, line in changed:            if line is None:                # pure deletion                del self.lines[s:e+1]            else:                self.lines[s:e+1] = [line]        f.writelines(self.lines)        # Copy over the remainder of the file.        if self.therest:            f.write(self.therest)if __name__ == '__main__':    main()