bpo-32775: Fix regular expression warnings in fnmatch. (#5583)
fnmatch.translate() no longer produces patterns which contain set
operations.
Sets starting with '[' or containing '--', '&&', '~~' or '||' will
be interpreted differently in regular expressions in future versions.
Currently they emit warnings. fnmatch.translate() now avoids producing
patterns containing such sets by accident.
diff --git a/Lib/fnmatch.py b/Lib/fnmatch.py
index fd3b514..b98e641 100644
--- a/Lib/fnmatch.py
+++ b/Lib/fnmatch.py
@@ -97,11 +97,30 @@
if j >= n:
res = res + '\\['
else:
- stuff = pat[i:j].replace('\\','\\\\')
+ stuff = pat[i:j]
+ if '--' not in stuff:
+ stuff = stuff.replace('\\', r'\\')
+ else:
+ chunks = []
+ k = i+2 if pat[i] == '!' else i+1
+ while True:
+ k = pat.find('-', k, j)
+ if k < 0:
+ break
+ chunks.append(pat[i:k])
+ i = k+1
+ k = k+3
+ chunks.append(pat[i:j])
+ # Escape backslashes and hyphens for set difference (--).
+ # Hyphens that create ranges shouldn't be escaped.
+ stuff = '-'.join(s.replace('\\', r'\\').replace('-', r'\-')
+ for s in chunks)
+ # Escape set operations (&&, ~~ and ||).
+ stuff = re.sub(r'([&~|])', r'\\\1', stuff)
i = j+1
if stuff[0] == '!':
stuff = '^' + stuff[1:]
- elif stuff[0] == '^':
+ elif stuff[0] in ('^', '['):
stuff = '\\' + stuff
res = '%s[%s]' % (res, stuff)
else: