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      1 #! /usr/bin/env python
      2 
      3 # This script is obsolete -- it is kept for historical purposes only.
      4 #
      5 # Fix Python source files to use the new class definition syntax, i.e.,
      6 # the syntax used in Python versions before 0.9.8:
      7 #       class C() = base(), base(), ...: ...
      8 # is changed to the current syntax:
      9 #       class C(base, base, ...): ...
     10 #
     11 # The script uses heuristics to find class definitions that usually
     12 # work but occasionally can fail; carefully check the output!
     13 #
     14 # Command line arguments are files or directories to be processed.
     15 # Directories are searched recursively for files whose name looks
     16 # like a python module.
     17 # Symbolic links are always ignored (except as explicit directory
     18 # arguments).  Of course, the original file is kept as a back-up
     19 # (with a "~" attached to its name).
     20 #
     21 # Changes made are reported to stdout in a diff-like format.
     22 #
     23 # Undoubtedly you can do this using find and sed or perl, but this is
     24 # a nice example of Python code that recurses down a directory tree
     25 # and uses regular expressions.  Also note several subtleties like
     26 # preserving the file's mode and avoiding to even write a temp file
     27 # when no changes are needed for a file.
     28 #
     29 # NB: by changing only the function fixline() you can turn this
     30 # into a program for a different change to Python programs...
     31 
     32 import sys
     33 import re
     34 import os
     35 from stat import *
     36 
     37 err = sys.stderr.write
     38 dbg = err
     39 rep = sys.stdout.write
     40 
     41 def main():
     42     bad = 0
     43     if not sys.argv[1:]: # No arguments
     44         err('usage: ' + sys.argv[0] + ' file-or-directory ...\n')
     45         sys.exit(2)
     46     for arg in sys.argv[1:]:
     47         if os.path.isdir(arg):
     48             if recursedown(arg): bad = 1
     49         elif os.path.islink(arg):
     50             err(arg + ': will not process symbolic links\n')
     51             bad = 1
     52         else:
     53             if fix(arg): bad = 1
     54     sys.exit(bad)
     55 
     56 ispythonprog = re.compile('^[a-zA-Z0-9_]+\.py$')
     57 def ispython(name):
     58     return ispythonprog.match(name) >= 0
     59 
     60 def recursedown(dirname):
     61     dbg('recursedown(%r)\n' % (dirname,))
     62     bad = 0
     63     try:
     64         names = os.listdir(dirname)
     65     except os.error, msg:
     66         err('%s: cannot list directory: %r\n' % (dirname, msg))
     67         return 1
     68     names.sort()
     69     subdirs = []
     70     for name in names:
     71         if name in (os.curdir, os.pardir): continue
     72         fullname = os.path.join(dirname, name)
     73         if os.path.islink(fullname): pass
     74         elif os.path.isdir(fullname):
     75             subdirs.append(fullname)
     76         elif ispython(name):
     77             if fix(fullname): bad = 1
     78     for fullname in subdirs:
     79         if recursedown(fullname): bad = 1
     80     return bad
     81 
     82 def fix(filename):
     83 ##  dbg('fix(%r)\n' % (filename,))
     84     try:
     85         f = open(filename, 'r')
     86     except IOError, msg:
     87         err('%s: cannot open: %r\n' % (filename, msg))
     88         return 1
     89     head, tail = os.path.split(filename)
     90     tempname = os.path.join(head, '@' + tail)
     91     g = None
     92     # If we find a match, we rewind the file and start over but
     93     # now copy everything to a temp file.
     94     lineno = 0
     95     while 1:
     96         line = f.readline()
     97         if not line: break
     98         lineno = lineno + 1
     99         while line[-2:] == '\\\n':
    100             nextline = f.readline()
    101             if not nextline: break
    102             line = line + nextline
    103             lineno = lineno + 1
    104         newline = fixline(line)
    105         if newline != line:
    106             if g is None:
    107                 try:
    108                     g = open(tempname, 'w')
    109                 except IOError, msg:
    110                     f.close()
    111                     err('%s: cannot create: %r\n' % (tempname, msg))
    112                     return 1
    113                 f.seek(0)
    114                 lineno = 0
    115                 rep(filename + ':\n')
    116                 continue # restart from the beginning
    117             rep(repr(lineno) + '\n')
    118             rep('< ' + line)
    119             rep('> ' + newline)
    120         if g is not None:
    121             g.write(newline)
    122 
    123     # End of file
    124     f.close()
    125     if not g: return 0 # No changes
    126 
    127     # Finishing touch -- move files
    128 
    129     # First copy the file's mode to the temp file
    130     try:
    131         statbuf = os.stat(filename)
    132         os.chmod(tempname, statbuf[ST_MODE] & 07777)
    133     except os.error, msg:
    134         err('%s: warning: chmod failed (%r)\n' % (tempname, msg))
    135     # Then make a backup of the original file as filename~
    136     try:
    137         os.rename(filename, filename + '~')
    138     except os.error, msg:
    139         err('%s: warning: backup failed (%r)\n' % (filename, msg))
    140     # Now move the temp file to the original file
    141     try:
    142         os.rename(tempname, filename)
    143     except os.error, msg:
    144         err('%s: rename failed (%r)\n' % (filename, msg))
    145         return 1
    146     # Return succes
    147     return 0
    148 
    149 # This expression doesn't catch *all* class definition headers,
    150 # but it's pretty darn close.
    151 classexpr = '^([ \t]*class +[a-zA-Z0-9_]+) *( *) *((=.*)?):'
    152 classprog = re.compile(classexpr)
    153 
    154 # Expressions for finding base class expressions.
    155 baseexpr = '^ *(.*) *( *) *$'
    156 baseprog = re.compile(baseexpr)
    157 
    158 def fixline(line):
    159     if classprog.match(line) < 0: # No 'class' keyword -- no change
    160         return line
    161 
    162     (a0, b0), (a1, b1), (a2, b2) = classprog.regs[:3]
    163     # a0, b0 = Whole match (up to ':')
    164     # a1, b1 = First subexpression (up to classname)
    165     # a2, b2 = Second subexpression (=.*)
    166     head = line[:b1]
    167     tail = line[b0:] # Unmatched rest of line
    168 
    169     if a2 == b2: # No base classes -- easy case
    170         return head + ':' + tail
    171 
    172     # Get rid of leading '='
    173     basepart = line[a2+1:b2]
    174 
    175     # Extract list of base expressions
    176     bases = basepart.split(',')
    177 
    178     # Strip trailing '()' from each base expression
    179     for i in range(len(bases)):
    180         if baseprog.match(bases[i]) >= 0:
    181             x1, y1 = baseprog.regs[1]
    182             bases[i] = bases[i][x1:y1]
    183 
    184     # Join the bases back again and build the new line
    185     basepart = ', '.join(bases)
    186 
    187     return head + '(' + basepart + '):' + tail
    188 
    189 if __name__ == '__main__':
    190     main()
    191