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Editing: classfix.py
#! /usr/bin/python2.7 # This script is obsolete -- it is kept for historical purposes only. # # Fix Python source files to use the new class definition syntax, i.e., # the syntax used in Python versions before 0.9.8: # class C() = base(), base(), ...: ... # is changed to the current syntax: # class C(base, base, ...): ... # # The script uses heuristics to find class definitions that usually # work but occasionally can fail; carefully check the output! # # Command line arguments are files or directories to be processed. # Directories are searched recursively for files whose name looks # like a python module. # Symbolic links are always ignored (except as explicit directory # arguments). Of course, the original file is kept as a back-up # (with a "~" attached to its name). # # Changes made are reported to stdout in a diff-like format. # # Undoubtedly you can do this using find and sed or perl, but this is # a nice example of Python code that recurses down a directory tree # and uses regular expressions. Also note several subtleties like # preserving the file's mode and avoiding to even write a temp file # when no changes are needed for a file. # # NB: by changing only the function fixline() you can turn this # into a program for a different change to Python programs... import sys import re import os from stat import * err = sys.stderr.write dbg = err rep = sys.stdout.write def main(): bad = 0 if not sys.argv[1:]: # No arguments err('usage: ' + sys.argv[0] + ' file-or-directory ...\n') sys.exit(2) for arg in sys.argv[1:]: if os.path.isdir(arg): if recursedown(arg): bad = 1 elif os.path.islink(arg): err(arg + ': will not process symbolic links\n') bad = 1 else: if fix(arg): bad = 1 sys.exit(bad) ispythonprog = re.compile('^[a-zA-Z0-9_]+\.py$') def ispython(name): return ispythonprog.match(name) >= 0 def recursedown(dirname): dbg('recursedown(%r)\n' % (dirname,)) bad = 0 try: names = os.listdir(dirname) except os.error, msg: err('%s: cannot list directory: %r\n' % (dirname, msg)) return 1 names.sort() subdirs = [] for name in names: if name in (os.curdir, os.pardir): continue fullname = os.path.join(dirname, name) if os.path.islink(fullname): pass elif os.path.isdir(fullname): subdirs.append(fullname) elif ispython(name): if fix(fullname): bad = 1 for fullname in subdirs: if recursedown(fullname): bad = 1 return bad def fix(filename): ## dbg('fix(%r)\n' % (filename,)) try: f = open(filename, 'r') except IOError, msg: err('%s: cannot open: %r\n' % (filename, msg)) return 1 head, tail = os.path.split(filename) tempname = os.path.join(head, '@' + tail) g = None # If we find a match, we rewind the file and start over but # now copy everything to a temp file. lineno = 0 while 1: line = f.readline() if not line: break lineno = lineno + 1 while line[-2:] == '\\\n': nextline = f.readline() if not nextline: break line = line + nextline lineno = lineno + 1 newline = fixline(line) if newline != line: if g is None: try: g = open(tempname, 'w') except IOError, msg: f.close() err('%s: cannot create: %r\n' % (tempname, msg)) return 1 f.seek(0) lineno = 0 rep(filename + ':\n') continue # restart from the beginning rep(repr(lineno) + '\n') rep('< ' + line) rep('> ' + newline) if g is not None: g.write(newline) # End of file f.close() if not g: return 0 # No changes # Finishing touch -- move files # First copy the file's mode to the temp file try: statbuf = os.stat(filename) os.chmod(tempname, statbuf[ST_MODE] & 07777) except os.error, msg: err('%s: warning: chmod failed (%r)\n' % (tempname, msg)) # Then make a backup of the original file as filename~ try: os.rename(filename, filename + '~') except os.error, msg: err('%s: warning: backup failed (%r)\n' % (filename, msg)) # Now move the temp file to the original file try: os.rename(tempname, filename) except os.error, msg: err('%s: rename failed (%r)\n' % (filename, msg)) return 1 # Return succes return 0 # This expression doesn't catch *all* class definition headers, # but it's pretty darn close. classexpr = '^([ \t]*class +[a-zA-Z0-9_]+) *( *) *((=.*)?):' classprog = re.compile(classexpr) # Expressions for finding base class expressions. baseexpr = '^ *(.*) *( *) *$' baseprog = re.compile(baseexpr) def fixline(line): if classprog.match(line) < 0: # No 'class' keyword -- no change return line (a0, b0), (a1, b1), (a2, b2) = classprog.regs[:3] # a0, b0 = Whole match (up to ':') # a1, b1 = First subexpression (up to classname) # a2, b2 = Second subexpression (=.*) head = line[:b1] tail = line[b0:] # Unmatched rest of line if a2 == b2: # No base classes -- easy case return head + ':' + tail # Get rid of leading '=' basepart = line[a2+1:b2] # Extract list of base expressions bases = basepart.split(',') # Strip trailing '()' from each base expression for i in range(len(bases)): if baseprog.match(bases[i]) >= 0: x1, y1 = baseprog.regs[1] bases[i] = bases[i][x1:y1] # Join the bases back again and build the new line basepart = ', '.join(bases) return head + '(' + basepart + '):' + tail if __name__ == '__main__': main()
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