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      1 #! /usr/bin/env python
      2 
      3 # Fix Python source files to avoid using
      4 #       def method(self, (arg1, ..., argn)):
      5 # instead of the more rational
      6 #       def method(self, arg1, ..., argn):
      7 #
      8 # Command line arguments are files or directories to be processed.
      9 # Directories are searched recursively for files whose name looks
     10 # like a python module.
     11 # Symbolic links are always ignored (except as explicit directory
     12 # arguments).  Of course, the original file is kept as a back-up
     13 # (with a "~" attached to its name).
     14 # It complains about binaries (files containing null bytes)
     15 # and about files that are ostensibly not Python files: if the first
     16 # line starts with '#!' and does not contain the string 'python'.
     17 #
     18 # Changes made are reported to stdout in a diff-like format.
     19 #
     20 # Undoubtedly you can do this using find and sed or perl, but this is
     21 # a nice example of Python code that recurses down a directory tree
     22 # and uses regular expressions.  Also note several subtleties like
     23 # preserving the file's mode and avoiding to even write a temp file
     24 # when no changes are needed for a file.
     25 #
     26 # NB: by changing only the function fixline() you can turn this
     27 # into a program for a different change to Python programs...
     28 
     29 import sys
     30 import re
     31 import os
     32 from stat import *
     33 
     34 err = sys.stderr.write
     35 dbg = err
     36 rep = sys.stdout.write
     37 
     38 def main():
     39     bad = 0
     40     if not sys.argv[1:]: # No arguments
     41         err('usage: ' + sys.argv[0] + ' file-or-directory ...\n')
     42         sys.exit(2)
     43     for arg in sys.argv[1:]:
     44         if os.path.isdir(arg):
     45             if recursedown(arg): bad = 1
     46         elif os.path.islink(arg):
     47             err(arg + ': will not process symbolic links\n')
     48             bad = 1
     49         else:
     50             if fix(arg): bad = 1
     51     sys.exit(bad)
     52 
     53 ispythonprog = re.compile('^[a-zA-Z0-9_]+\.py$')
     54 def ispython(name):
     55     return ispythonprog.match(name) >= 0
     56 
     57 def recursedown(dirname):
     58     dbg('recursedown(%r)\n' % (dirname,))
     59     bad = 0
     60     try:
     61         names = os.listdir(dirname)
     62     except os.error, msg:
     63         err('%s: cannot list directory: %r\n' % (dirname, msg))
     64         return 1
     65     names.sort()
     66     subdirs = []
     67     for name in names:
     68         if name in (os.curdir, os.pardir): continue
     69         fullname = os.path.join(dirname, name)
     70         if os.path.islink(fullname): pass
     71         elif os.path.isdir(fullname):
     72             subdirs.append(fullname)
     73         elif ispython(name):
     74             if fix(fullname): bad = 1
     75     for fullname in subdirs:
     76         if recursedown(fullname): bad = 1
     77     return bad
     78 
     79 def fix(filename):
     80 ##  dbg('fix(%r)\n' % (filename,))
     81     try:
     82         f = open(filename, 'r')
     83     except IOError, msg:
     84         err('%s: cannot open: %r\n' % (filename, msg))
     85         return 1
     86     head, tail = os.path.split(filename)
     87     tempname = os.path.join(head, '@' + tail)
     88     g = None
     89     # If we find a match, we rewind the file and start over but
     90     # now copy everything to a temp file.
     91     lineno = 0
     92     while 1:
     93         line = f.readline()
     94         if not line: break
     95         lineno = lineno + 1
     96         if g is None and '\0' in line:
     97             # Check for binary files
     98             err(filename + ': contains null bytes; not fixed\n')
     99             f.close()
    100             return 1
    101         if lineno == 1 and g is None and line[:2] == '#!':
    102             # Check for non-Python scripts
    103             words = line[2:].split()
    104             if words and re.search('[pP]ython', words[0]) < 0:
    105                 msg = filename + ': ' + words[0]
    106                 msg = msg + ' script; not fixed\n'
    107                 err(msg)
    108                 f.close()
    109                 return 1
    110         while line[-2:] == '\\\n':
    111             nextline = f.readline()
    112             if not nextline: break
    113             line = line + nextline
    114             lineno = lineno + 1
    115         newline = fixline(line)
    116         if newline != line:
    117             if g is None:
    118                 try:
    119                     g = open(tempname, 'w')
    120                 except IOError, msg:
    121                     f.close()
    122                     err('%s: cannot create: %r\n' % (tempname, msg))
    123                     return 1
    124                 f.seek(0)
    125                 lineno = 0
    126                 rep(filename + ':\n')
    127                 continue # restart from the beginning
    128             rep(repr(lineno) + '\n')
    129             rep('< ' + line)
    130             rep('> ' + newline)
    131         if g is not None:
    132             g.write(newline)
    133 
    134     # End of file
    135     f.close()
    136     if not g: return 0 # No changes
    137 
    138     # Finishing touch -- move files
    139 
    140     # First copy the file's mode to the temp file
    141     try:
    142         statbuf = os.stat(filename)
    143         os.chmod(tempname, statbuf[ST_MODE] & 07777)
    144     except os.error, msg:
    145         err('%s: warning: chmod failed (%r)\n' % (tempname, msg))
    146     # Then make a backup of the original file as filename~
    147     try:
    148         os.rename(filename, filename + '~')
    149     except os.error, msg:
    150         err('%s: warning: backup failed (%r)\n' % (filename, msg))
    151     # Now move the temp file to the original file
    152     try:
    153         os.rename(tempname, filename)
    154     except os.error, msg:
    155         err('%s: rename failed (%r)\n' % (filename, msg))
    156         return 1
    157     # Return succes
    158     return 0
    159 
    160 
    161 fixpat = '^[ \t]+def +[a-zA-Z0-9_]+ *( *self *, *(( *(.*) *)) *) *:'
    162 fixprog = re.compile(fixpat)
    163 
    164 def fixline(line):
    165     if fixprog.match(line) >= 0:
    166         (a, b), (c, d) = fixprog.regs[1:3]
    167         line = line[:a] + line[c:d] + line[b:]
    168     return line
    169 
    170 if __name__ == '__main__':
    171     main()
    172