Add benchmark importing all standard library modules (#338)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Stan Ulbrych <stan@python.org>
Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>
Co-authored-by: Michael Droettboom <mdboom@gmail.com>

Author: 5 people

pyperformance/data-files/benchmarks/MANIFEST

@@ -92,6 +92,7 @@ sqlglot_v2_parse	<local:sqlglot_v2>
 sqlglot_v2_transpile	<local:sqlglot_v2>
 sqlglot_v2_optimize	<local:sqlglot_v2>
 sqlite_synth	<local>
+stdlib_startup	<local>
 sympy	<local>
 telco	<local>
 tomli_loads	<local>

pyperformance/data-files/benchmarks/bm_stdlib_startup/pyproject.toml

@@ -0,0 +1,10 @@
+[project]
+name = "pyperformance_stdlib_startup"
+requires-python = ">=3.10"
+dependencies = []
+urls = {repository = "https://github.com/python/pyperformance"}
+dynamic = ["version"]
+
+[tool.pyperformance]
+name = "stdlib_startup"
+tags = "startup"

pyperformance/data-files/benchmarks/bm_stdlib_startup/requirements.txt

@@ -0,0 +1,34 @@
+"""
+Measures the time it takes to import all the modules (excluding those with
+import side effects) in the stdlib.
+
+This benchmark is expected to change as the stdlib changes, so it is not
+suitable for measuring compilation time.
+"""
+
+import os
+import sys
+import subprocess
+import tempfile
+
+import pyperf
+
+if __name__ == "__main__":
+    runner = pyperf.Runner(values=10)
+
+    runner.metadata['description'] = "Performance of importing standard library modules"
+    args = runner.parse_args()
+
+    with tempfile.TemporaryDirectory() as tmp:
+        main = os.path.join(tmp, "main.py")
+        modules_to_import = sorted(sys.stdlib_module_names - {'antigravity', 'this'})
+        with open(main, 'w', encoding='utf-8') as f:
+            for module in modules_to_import:
+                f.write(f"""
+try:
+    import {module}
+except ImportError:
+    pass
+""")
+        command = [sys.executable, main]
+        runner.bench_command('stdlib_startup', command)