-x/--exclude option, closes #27

README.md

@@ -55,10 +55,14 @@ To search within a specific file, pass that file using the `-f` option. You can
 ```bash
 symbex MyClass -f my_file.py
 ```
-To search within a specific directory and all of its subdirectories, use the `-d` option:
+To search within a specific directory and all of its subdirectories, use the `-d/--directory` option:
 ```bash
 symbex Database -d ~/projects/datasette
 ```
+You can exclude files in specified directories using the `-x/--exclude` option:
+```bash
+symbex Database -d ~/projects/datasette -x ~/projects/datasette/tests
+```
 If `symbex` encounters any Python code that it cannot parse, it will print a warning message and continue searching:
 ```
 # Syntax error in path/badcode.py: expected ':' (<unknown>, line 1)
@@ -301,6 +305,7 @@ Options:
   --version                  Show the version and exit.
   -f, --file FILE            Files to search
   -d, --directory DIRECTORY  Directories to search
+  -x, --exclude DIRECTORY    Directories to exclude
   -s, --signatures           Show just function and class signatures
   --docstrings               Show function and class signatures plus docstrings
   --count                    Show count of matching symbols

symbex/cli.py

@@ -24,6 +24,14 @@
     multiple=True,
     help="Directories to search",
 )
+@click.option(
+    "excludes",
+    "-x",
+    "--exclude",
+    type=click.Path(file_okay=False, dir_okay=True, resolve_path=True),
+    multiple=True,
+    help="Directories to exclude",
+)
 @click.option(
     "-s",
     "--signatures",
@@ -96,6 +104,7 @@ def cli(
     symbols,
     files,
     directories,
+    excludes,
     signatures,
     docstrings,
     count,
@@ -198,10 +207,15 @@ def cli(
     if not files and not directories:
         directories = ["."]
 
+    excludes = [pathlib.Path(exclude) for exclude in excludes]
+
     def iterate_files():
         yield from (pathlib.Path(f) for f in files)
         for directory in directories:
             for path in pathlib.Path(directory).rglob("*.py"):
+                # Skip if path is inside any of 'excludes'
+                if any(is_subpath(path, exclude) for exclude in excludes):
+                    continue
                 if path.is_file():
                     yield path
 
@@ -288,3 +302,11 @@ def filter(node: ast.AST) -> bool:
             print()
     if count:
         click.echo(num_matches)
+
+
+def is_subpath(path: pathlib.Path, parent: pathlib.Path) -> bool:
+    try:
+        path.relative_to(parent)
+        return True
+    except ValueError:
+        return False

tests/test_symbex.py

@@ -19,7 +19,7 @@ def directory_full_of_code(tmpdir):
     for path, content in (
         ("foo.py", "def foo1():\n    pass\n\n@decorated\ndef foo2():\n    pass\n\n"),
         ("bar.py", "class BarClass:\n    pass\n\n"),
-        ("nested.py/baz.py", 'def baz(delimiter=", ", type=str):\n    pass\n\n'),
+        ("nested.py/x/baz.py", 'def baz(delimiter=", ", type=str):\n    pass\n\n'),
         ("nested.py/error.py", "def baz_error()" + "bug:\n    pass\n\n"),
         (
             "methods.py",
@@ -68,21 +68,26 @@ async def async_method(a, b, c):
         ),
         (
             ["baz", "--silent"],
-            '# File: nested.py/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
+            '# File: nested.py/x/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
         ),
         (
             ["async_func", "--silent"],
             "# File: async.py Line: 1\nasync def async_func(a, b, c):\n    pass\n\n",
         ),
         # The -f option
         (
-            ["baz", "-f", "nested.py/baz.py", "--silent"],
-            '# File: nested.py/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
+            ["baz", "-f", "nested.py/x/baz.py", "--silent"],
+            '# File: nested.py/x/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
         ),
         # The -d option
         (
             ["baz", "-d", "nested.py", "--silent"],
-            '# File: nested.py/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
+            '# File: nested.py/x/baz.py Line: 1\ndef baz(delimiter=", ", type=str):\n    pass\n\n',
+        ),
+        # The -d option with -x to exclude
+        (
+            ["baz", "-d", "nested.py", "-x", "nested.py/x/", "--silent"],
+            "",
         ),
         # Classes
         (
@@ -154,7 +159,10 @@ def test_fixture(directory_full_of_code, monkeypatch, args, expected):
         (["BarClass", "--silent"], "# File: bar.py Line: 1\n" "class BarClass"),
         (
             ["baz", "--silent"],
-            ("# File: nested.py/baz.py Line: 1\n" 'def baz(delimiter=", ", type=str)'),
+            (
+                "# File: nested.py/x/baz.py Line: 1\n"
+                'def baz(delimiter=", ", type=str)'
+            ),
         ),
     ),
 )
@@ -174,7 +182,7 @@ def test_errors(directory_full_of_code, monkeypatch):
     result = runner.invoke(cli, ["baz"], catch_exceptions=False)
     assert result.exit_code == 0
     expected = (
-        "# File: nested.py/baz.py Line: 1\n"
+        "# File: nested.py/x/baz.py Line: 1\n"
         'def baz(delimiter=", ", type=str):\n'
         "    pass\n\n"
     )