1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
#! /usr/bin/env python
# Fix Python source files to use the new equality test operator, i.e.,
# if x = y: ...
# is changed to
# if x == y: ...
# The script correctly tokenizes the Python program to reliably
# distinguish between assignments and equality tests.
#
# 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).
# It complains about binaries (files containing null bytes)
# and about files that are ostensibly not Python files: if the first
# line starts with '#!' and does not contain the string 'python'.
#
# 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 *
import string
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' % (dirname,))
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
if g is None and '\0' in line:
# Check for binary files
err(filename + ': contains null bytes; not fixed\n')
f.close()
return 1
if lineno == 1 and g is None and line[:2] == '#!':
# Check for non-Python scripts
words = string.split(line[2:])
if words and re.search('[pP]ython', words[0]) < 0:
msg = filename + ': ' + words[0]
msg = msg + ' script; not fixed\n'
err(msg)
f.close()
return 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
from tokenize import tokenprog
match = {'if':':', 'elif':':', 'while':':', 'return':'\n', \
'(':')', '[':']', '{':'}', '`':'`'}
def fixline(line):
# Quick check for easy case
if '=' not in line: return line
i, n = 0, len(line)
stack = []
while i < n:
j = tokenprog.match(line, i)
if j < 0:
# A bad token; forget about the rest of this line
print '(Syntax error:)'
print line,
return line
a, b = tokenprog.regs[3] # Location of the token proper
token = line[a:b]
i = i+j
if stack and token == stack[-1]:
del stack[-1]
elif match.has_key(token):
stack.append(match[token])
elif token == '=' and stack:
line = line[:a] + '==' + line[b:]
i, n = a + len('=='), len(line)
elif token == '==' and not stack:
print '(Warning: \'==\' at top level:)'
print line,
return line
if __name__ == "__main__":
main()
|
