docs: add an example on measuring import times

Author: art049

pyproject.toml

@@ -118,7 +118,7 @@ float_to_top = true
 [tool.pytest.ini_options]
 addopts = "--ignore=tests/benchmarks --ignore=tests/examples --ignore=tests/benchmarks/TheAlgorithms"
 filterwarnings = ["ignore::DeprecationWarning:pytest_benchmark.utils.*:"]
-pythonpath = ["tests/benchmarks/TheAlgorithms", "./scripts"]
+pythonpath = ["tests/benchmarks/TheAlgorithms", "./scripts", "tests/benchmarks"]
 
 [tool.coverage.run]
 branch = true

tests/benchmarks/test_bench_imports/__init__.py

@@ -0,0 +1,3 @@
+# Fake import initialization payload
+for i in range(10000):
+    pass

tests/benchmarks/test_bench_imports/module_a.py

@@ -0,0 +1,5 @@
+# Depends on module_a.py
+from . import module_a
+# Fake import initialization payload
+for i in range(10000):
+    pass

tests/benchmarks/test_bench_imports/module_b.py

@@ -0,0 +1,14 @@
+import importlib
+import sys
+import time
+import pytest
+from unittest import mock
+
+@pytest.mark.parametrize("mod_name", [".module_a", ".module_b"])
+def test_bench_module_import(benchmark, mod_name):
+    @benchmark
+    def _():
+        with mock.patch("sys.modules", {}):
+            importlib.import_module(mod_name, "test_bench_imports")
+
+