match using re.search and use anchors

tests/arguments.py

@@ -231,10 +231,10 @@ def test_exclude_regex(self):
     self.assertContainsDict({"code": 1}, self.parse_args(["--exclude-regex"]))  # Needs <rx> part.
     self.assertEmpty(self.config.exclusion_regex())
 
-    args = ["--exclude-regex", r".+\.pyi",
-            "--exclude-regex", "a/b"]
+    args = ["--exclude-regex", r"\.pyi$",
+            "--exclude-regex", "^a/b$"]
     self.assertContainsDict({"code": 0}, self.parse_args(args))
-    expected = [re.compile(r".+\.pyi"), re.compile("a/b")]
+    expected = [re.compile(r"\.pyi$"), re.compile("^a/b$")]
     self.assertEqual(expected, self.config.exclusion_regex())  # Expect it sorted.
     self.assertFalse(self.config.is_excluded_by_regex("a/b.py"))
     self.assertTrue(self.config.is_excluded_by_regex("asdf.pyi"))
@@ -249,8 +249,8 @@ def test_exclude_regex(self):
     self.assertFalse(self.config.is_excluded_by_regex("a/b/c.py"))
 
     self.config.reset()
-    args = ["--exclude-regex", "a/b/.+",
-            "--exclude-regex", r"a/.+/.+\.pyi"]
+    args = ["--exclude-regex", "^a/b/.+$",
+            "--exclude-regex", r"^a/.+/.+\.pyi$"]
     self.assertContainsDict({"code": 0}, self.parse_args(args))
     self.assertTrue(self.config.is_excluded_by_regex("a/b/c.py"))
     self.assertTrue(self.config.is_excluded_by_regex("a/b/c/d.py"))
@@ -261,7 +261,7 @@ def test_exclude_regex(self):
 
     self.config.reset()
     # Use '[^/]+' instead of '.+' to force only matching files in the top-level.
-    self.assertContainsDict({"code": 0}, self.parse_args(["--exclude-regex", r"a/b/[^/]+\.pyi"]))
+    self.assertContainsDict({"code": 0}, self.parse_args(["--exclude-regex", r"^a/b/[^/]+\.pyi$"]))
     self.assertTrue(self.config.is_excluded_by_regex("a/b/c.pyi"))
     self.assertFalse(self.config.is_excluded_by_regex("a/b/c.py"))
     self.assertFalse(self.config.is_excluded_by_regex("a/b/c/d.pyi"))

tests/general.py

@@ -322,7 +322,7 @@ def test_exclude_pyi_regex(self):
     # With the default of --make-paths-absolute, this will match .pyi files in any subdirectory. The
     # most common use case for --exclude-regex is expected to be for file extensions, so it's great
     # that that will work regardless of the --make-paths-absolute setting.
-    self.config.add_exclusion_regex(r".+\.pyi")
+    self.config.add_exclusion_regex(r"\.pyi$")
 
     f = touch(tmp_fld, "code.pyi")
     with open_wrapper(f, mode="w", encoding="utf-8") as fp:
@@ -337,7 +337,7 @@ def test_exclude_directory_regex(self):
     tmp_fld = mkdtemp()
 
     # Excluding the directory .../a should exclude any files recursively beneath it as well.
-    self.config.add_exclusion_regex(re.escape(join(tmp_fld, "a")))
+    self.config.add_exclusion_regex('^' + re.escape(join(tmp_fld, "a")) + '$')
 
     # Create .../a and .../a/b directories.
     os.mkdir(join(tmp_fld, "a"))
@@ -359,8 +359,8 @@ def test_exclude_regex_relative(self):
 
     # Keep paths relative, and provide patterns matching relative paths.
     self.config.set_make_paths_absolute(False)
-    self.config.add_exclusion_regex("a/b")
-    self.config.add_exclusion_regex("a/[^/]+\.pyi")
+    self.config.add_exclusion_regex("^a/b$")
+    self.config.add_exclusion_regex(r"^a/[^/]+\.pyi$")
 
     # Create .../a and .../a/b directories.
     os.mkdir(join(tmp_fld, "a"))

vermin/arguments.py

@@ -156,14 +156,16 @@ def print_usage(full=False):
             "        Use no excludes. Clears any excludes specified before this.")
       print("\n  [--exclude-regex <regex pattern>] ...\n"
             "        Exclude files from analysis by matching a regex pattern against their\n"
-            "        entire path as expanded from the vermin command line.\n\n"
+            "        entire path as expanded from the vermin command line. Patterns are matched\n"
+            "        using re.search(), so '^' or '$' anchors should be applied as needed.\n\n"
             "        Examples:\n"
-            "          Exclude any '.pyi' file:                --exclude-regex '.+\\.pyi'\n\n"
+            "          Exclude any '.pyi' file:                --exclude-regex '\\.pyi$'\n\n"
             "          (Note: the below examples require --no-make-paths-absolute, or prefixing\n"
-            "          the patterns with the absolute path to the current directory.)\n\n"
-            "          Exclude the directory 'a/b/':           --exclude-regex 'a/b'\n"
-            "          Exclude '.pyi' files under 'a/b/':      --exclude-regex 'a/b/.+\\.pyi'\n"
-            "          Exclude '.pyi' files in exactly 'a/b/': --exclude-regex 'a/b/[^/]+\\.pyi'")
+            "          the patterns with the regex-escaped path to the current directory.)\n\n"
+            "          Exclude the directory 'a/b/':           --exclude-regex '^a/b$'\n"
+            "            (This will also exclude any files under 'a/b'.)\n\n"
+            "          Exclude '.pyi' files under 'a/b/':      --exclude-regex '^a/b/.+\\.pyi$'\n"
+            "          Exclude '.pyi' files in exactly 'a/b/': --exclude-regex '^a/b/[^/]+\\.pyi$'")
       print("\n  --no-exclude-regex (default)\n"
             "        Use no exclude patterns. Clears any exclude patterns specified before this.")
       print("\n  --make-paths-absolute (default)\n"

vermin/config.py

@@ -335,12 +335,7 @@ def is_excluded_codecs_encoding(self, name):
     return "ce={}".format(name) in self.__exclusions
 
   def is_excluded_by_regex(self, path):
-    def matches_completely(rx, p):
-      m = rx.match(p)
-      if m is None:
-        return False
-      return m.end() == m.endpos
-    return any(matches_completely(regex, path) for regex in self.__exclusion_regex)
+    return any(regex.search(path) for regex in self.__exclusion_regex)
 
   def make_paths_absolute(self):
     return self.__make_paths_absolute