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Edit File: cleanfuture.py

#! /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 features from such statements that are already mandatory in the version of Python you'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 is given, likewise recursively for subdirectories. Overwrites files in place, renaming the originals with a .bak extension. If cleanfuture finds nothing to change, the file is left alone. If cleanfuture does change a file, the changed file is a fixed-point (i.e., running cleanfuture on the resulting .py file won't change it again, at least not until 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 tokenize import os import sys dryrun = 0 recurse = 0 verbose = 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()