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| 1 | +#! /usr/local/python |
| 2 | + |
| 3 | +# Fix Python source files to use the new class definition syntax, |
| 4 | +# i.e., |
| 5 | +# class C(base, base, ...): ... |
| 6 | +# instead of |
| 7 | +# class C() = base(), base(), ...: ... |
| 8 | +# |
| 9 | +# Command line arguments are files or directories to be processed. |
| 10 | +# Directories are searched recursively for files whose name looks |
| 11 | +# like a python module. |
| 12 | +# Symbolic links are always ignored (except as explicit directory |
| 13 | +# arguments). Of course, the original file is kept as a back-up |
| 14 | +# (with a "~" attached to its name). |
| 15 | +# |
| 16 | +# Undoubtedly you can do this using find and sed, but this is |
| 17 | +# a nice example of Python code that recurses down a directory tree |
| 18 | +# and uses regular expressions. Also note several subtleties like |
| 19 | +# preserving the file's mode and avoiding to even write a temp file |
| 20 | +# when no changes are needed for a file. |
| 21 | +# |
| 22 | +# Changes made are reported to stdout in a diff-like format. |
| 23 | + |
| 24 | +import sys |
| 25 | +import regexp |
| 26 | +import posix |
| 27 | +import path |
| 28 | +import string |
| 29 | +from stat import * |
| 30 | + |
| 31 | +err = sys.stderr.write |
| 32 | +dbg = err |
| 33 | +rep = sys.stdout.write |
| 34 | + |
| 35 | +def main(): |
| 36 | + bad = 0 |
| 37 | + if not sys.argv[1:]: # No arguments |
| 38 | + err('usage: classfix file-or-directory ...\n') |
| 39 | + sys.exit(2) |
| 40 | + for arg in sys.argv[1:]: |
| 41 | + if path.isdir(arg): |
| 42 | + if recursedown(arg): bad = 1 |
| 43 | + elif path.islink(arg): |
| 44 | + err(arg + ': will not process symbolic links\n') |
| 45 | + bad = 1 |
| 46 | + else: |
| 47 | + if fix(arg): bad = 1 |
| 48 | + sys.exit(bad) |
| 49 | + |
| 50 | +ispython = regexp.compile('^[a-zA-Z0-9_]+\.py$').match # This is a method! |
| 51 | + |
| 52 | +def recursedown(dirname): |
| 53 | + dbg('recursedown(' + `dirname` + ')\n') |
| 54 | + bad = 0 |
| 55 | + try: |
| 56 | + names = posix.listdir(dirname) |
| 57 | + except posix.error, msg: |
| 58 | + err(dirname + ': cannot list directory: ' + `msg` + '\n') |
| 59 | + return 1 |
| 60 | + for name in names: |
| 61 | + if name in ('.', '..'): continue |
| 62 | + fullname = path.join(dirname, name) |
| 63 | + if path.islink(fullname): pass |
| 64 | + elif path.isdir(fullname): |
| 65 | + if recursedown(fullname): bad = 1 |
| 66 | + elif ispython(name): |
| 67 | + if fix(fullname): bad = 1 |
| 68 | + return bad |
| 69 | + |
| 70 | +# This expression doesn't catch *all* class definition headers, |
| 71 | +# but it's darn pretty close. |
| 72 | +classexpr = '^([ \t]*class +[a-zA-Z0-9_]+) *\( *\) *((=.*)?):' |
| 73 | +findclass = regexp.compile(classexpr).match # This is a method! |
| 74 | + |
| 75 | +baseexpr = '^ *(.*) *\( *\) *$' |
| 76 | +findbase = regexp.compile(baseexpr).match # This is a method, too! |
| 77 | + |
| 78 | +def fix(filename): |
| 79 | +## dbg('fix(' + `filename` + ')\n') |
| 80 | + try: |
| 81 | + f = open(filename, 'r') |
| 82 | + except IOError, msg: |
| 83 | + err(filename + ': cannot open: ' + `msg` + '\n') |
| 84 | + return 1 |
| 85 | + head, tail = path.split(filename) |
| 86 | + tempname = path.join(head, '@' + tail) |
| 87 | + tf = None |
| 88 | + # If we find a match, we rewind the file and start over but |
| 89 | + # now copy everything to a temp file. |
| 90 | + while 1: |
| 91 | + line = f.readline() |
| 92 | + if not line: break |
| 93 | + res = findclass(line) |
| 94 | + if not res: |
| 95 | + if tf: tf.write(line) |
| 96 | + continue |
| 97 | + if not tf: |
| 98 | + try: |
| 99 | + tf = open(tempname, 'w') |
| 100 | + except IOError, msg: |
| 101 | + f.close() |
| 102 | + err(tempname+': cannot create: '+`msg`+'\n') |
| 103 | + return 1 |
| 104 | + rep(filename + ':\n') |
| 105 | + # Rewind the input file and start all over: |
| 106 | + f.seek(0) |
| 107 | + continue |
| 108 | + a0, b0 = res[0] # Whole match (up to ':') |
| 109 | + a1, b1 = res[1] # First subexpression (up to classname) |
| 110 | + a2, b2 = res[2] # Second subexpression (=.*) |
| 111 | + head = line[:b1] |
| 112 | + tail = line[b0:] # Unmatched rest of line |
| 113 | + if a2 = b2: # No base classes -- easy case |
| 114 | + newline = head + ':' + tail |
| 115 | + else: |
| 116 | + # Get rid of leading '=' |
| 117 | + basepart = line[a2+1:b2] |
| 118 | + # Extract list of base expressions |
| 119 | + bases = string.splitfields(basepart, ',') |
| 120 | + # Strip trailing '()' from each base expression |
| 121 | + for i in range(len(bases)): |
| 122 | + res = findbase(bases[i]) |
| 123 | + if res: |
| 124 | + (x0, y0), (x1, y1) = res |
| 125 | + bases[i] = bases[i][x1:y1] |
| 126 | + # Join the bases back again and build the new line |
| 127 | + basepart = string.joinfields(bases, ', ') |
| 128 | + newline = head + '(' + basepart + '):' + tail |
| 129 | + rep('< ' + line) |
| 130 | + rep('> ' + newline) |
| 131 | + tf.write(newline) |
| 132 | + f.close() |
| 133 | + if not tf: return 0 # No changes |
| 134 | + |
| 135 | + # Finishing touch -- move files |
| 136 | + |
| 137 | + # First copy the file's mode to the temp file |
| 138 | + try: |
| 139 | + statbuf = posix.stat(filename) |
| 140 | + posix.chmod(tempname, statbuf[ST_MODE] & 0x7777) |
| 141 | + except posix.error, msg: |
| 142 | + err(tempname + ': warning: chmod failed (' + `msg` + ')\n') |
| 143 | + # Then make a backup of the original file as filename~ |
| 144 | + try: |
| 145 | + posix.rename(filename, filename + '~') |
| 146 | + except posix.error, msg: |
| 147 | + err(filename + ': warning: backup failed (' + `msg` + ')\n') |
| 148 | + # Now move the temp file to the original file |
| 149 | + try: |
| 150 | + posix.rename(tempname, filename) |
| 151 | + except posix.error, msg: |
| 152 | + err(filename + ': rename failed (' + `msg` + ')\n') |
| 153 | + return 1 |
| 154 | + # Return succes |
| 155 | + return 0 |
| 156 | + |
| 157 | +main() |
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