#! /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 containing from __future__ import nested_scopes, generators is analyzed by cleanfuture, the line is rewritten to from __future__ import generators because nested_scopes is no longer optional in 2.2 but generators is.""" import __future__import tokenizeimport osimport sys dryrun  = 0recurse = 0verbose = 0 def 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()