Add -k to pytest-benchmark compare, just like pytest -k

Author: akx

CHANGELOG.rst

@@ -2,6 +2,11 @@
 Changelog
 =========
 
+v5.2.4 (unreleased)
+--------------------
+
+* Added ``-k`` filter option to the ``compare`` CLI command, using the same expression syntax as pytest's ``-k`` option.
+
 v5.2.3 (2025-11-09)
 --------------------
 

docs/usage.rst

@@ -235,6 +235,9 @@ The compare ``command`` takes almost all the ``--benchmark`` options, minus the
       --csv=FILENAME        Save a csv report. If FILENAME contains slashes ('/')
                             then directories will be created. Default:
                             'benchmark_<date>_<time>'
+      -k EXPR               Only show benchmarks matching the given expression.
+                            Uses the same syntax as pytest's ``-k`` option
+                            (e.g. ``'foo and not bar'``).
 
     examples:
 

src/pytest_benchmark/cli.py

@@ -110,6 +110,13 @@ def make_parser():
     add_histogram_options(compare_command.add_argument, prefix='')
     add_glob_or_file(compare_command.add_argument)
     add_csv_options(compare_command.add_argument, prefix='')
+    compare_command.add_argument(
+        '-k',
+        metavar='EXPR',
+        dest='filter_expr',
+        default=None,
+        help="Only show benchmarks matching the given expression. Uses the same syntax as pytest's -k option (e.g. 'foo and not bar').",
+    )
 
     return parser
 
@@ -159,8 +166,19 @@ def main():
                 config=Config.fromdictargs({'benchmark_time_unit': args.time_unit}, []),
             ),
         )
+        benchmarks = storage.load_benchmarks(*args.glob_or_file)
+        if args.filter_expr:
+            from _pytest.mark.expression import Expression  # noqa: PLC0415
+
+            expr = Expression.compile(args.filter_expr)
+
+            def _evaluate_expr(benchmark):
+                name = benchmark.get('fullname') or benchmark.get('name', '')
+                return expr.evaluate(lambda key: key in name)
+
+            benchmarks = filter(_evaluate_expr, benchmarks)
         groups = hook.pytest_benchmark_group_stats(
-            benchmarks=storage.load_benchmarks(*args.glob_or_file),
+            benchmarks=benchmarks,
             group_by=args.group_by,
             config=None,
         )

tests/test_cli.py

@@ -93,7 +93,7 @@ def test_help_compare(testdir, args):
             '                                 [--columns LABELS] [--name FORMAT]',
             '                                 [--time-unit COLUMN]',
             '                                 [--histogram [FILENAME-PREFIX]]',
-            '                                 [--csv [FILENAME]]',
+            '                                 [--csv [FILENAME]] [-k EXPR]',
             '                                 [[]glob_or_file *[]]',
             '',
             'Compare saved runs.',
@@ -125,6 +125,9 @@ def test_help_compare(testdir, args):
             "  --csv [FILENAME]      Save a csv report. If FILENAME contains slashes ('/')",
             '                        then directories will be created. Default:',
             "                        'benchmark_*'",
+            '  -k EXPR               Only show benchmarks matching the given expression.',
+            "                        Uses the same syntax as pytest's -k option (e.g. 'foo",
+            "                        and not bar').",
             '',
             'examples:',
             '',
@@ -358,3 +361,35 @@ def func():
     )
     result = testdir.run('py.test-benchmark', 'compare', '--csv')
     result.stderr.fnmatch_lines(['Generated csv: *.csv'])
+
+
+def test_compare_filter(testdir):
+    test = testdir.makepyfile("""
+    import pytest
+    @pytest.mark.parametrize("arg", ["foo", "bar"])
+    def test_alpha(benchmark, arg):
+        benchmark(lambda: None)
+    def test_beta(benchmark):
+        benchmark(lambda: None)
+    """)
+    result = testdir.runpytest_subprocess('--benchmark-autosave', test)
+    result.stderr.fnmatch_lines(['Saved benchmark data in: *'])
+
+    # Filter to only test_alpha benchmarks
+    result = testdir.run('py.test-benchmark', 'compare', '-k', 'alpha', '--columns', 'min,max')
+    result.stdout.fnmatch_lines(['*benchmark: 2 tests*'])
+    assert 'test_beta' not in result.stdout.str()
+
+    # Filter with "not" expression
+    result = testdir.run('py.test-benchmark', 'compare', '-k', 'not alpha', '--columns', 'min,max')
+    result.stdout.fnmatch_lines(['*benchmark: 1 tests*'])
+    assert 'test_alpha' not in result.stdout.str()
+
+    # Filter with "and" expression
+    result = testdir.run('py.test-benchmark', 'compare', '-k', 'alpha and foo', '--columns', 'min,max')
+    result.stdout.fnmatch_lines(['*benchmark: 1 tests*'])
+    assert 'bar' not in result.stdout.str()
+
+    # No filter shows all
+    result = testdir.run('py.test-benchmark', 'compare', '--columns', 'min,max')
+    result.stdout.fnmatch_lines(['*benchmark: 3 tests*'])