Require envfile extra for .env support

README.md

@@ -70,6 +70,8 @@ pytest-env:
 
 ### Load variables from `.env` files
 
+Install the plugin with the `[envfile]` extra to enable `.env` file support.
+
 Specify `.env` files in your configuration:
 
 ```toml

pyproject.toml

@@ -38,9 +38,11 @@ dynamic = [
 ]
 dependencies = [
   "pytest>=9.0.2",
-  "python-dotenv>=1.2.1",
   "tomli>=2.4; python_version<'3.11'",
 ]
+optional-dependencies.envfile = [
+  "python-dotenv>=1.2.1",
+]
 optional-dependencies.testing = [
   "covdefaults>=2.3",
   "coverage>=7.13.4",

src/pytest_env/plugin.py

@@ -8,7 +8,6 @@
 from typing import TYPE_CHECKING, Any
 
 import pytest
-from dotenv import dotenv_values
 
 if TYPE_CHECKING:
     from collections.abc import Generator, Iterator
@@ -75,13 +74,22 @@ def pytest_load_initial_conftests(
         early_config.stash[_env_actions_key] = _format_actions(actions)
 
 
+def _dotenv_values(env_file: Path) -> dict[str, str | None]:
+    try:
+        from dotenv import dotenv_values  # noqa: PLC0415 (late import on purpose)
+    except ModuleNotFoundError:
+        msg = "python-dotenv is required for env file support; install pytest-env[envfile]"
+        raise ImportError(msg) from None
+    return dotenv_values(env_file)
+
+
 def _apply_env_files(
     early_config: pytest.Config,
     env_files_list: list[str],
     actions: list[tuple[str, str, str, str]] | None,
 ) -> None:
     for env_file in _load_env_files(early_config, env_files_list):
-        for key, value in dotenv_values(env_file).items():
+        for key, value in _dotenv_values(env_file).items():
             if value is not None:
                 os.environ[key] = value
                 if actions is not None:

tox.toml

@@ -2,7 +2,7 @@
 description = "run the tests with pytest"
 package = "wheel"
 wheel_build_env = ".pkg"
-extras = [ "testing" ]
+extras = [ "testing", "envfile" ]
 pass_env = [ "DIFF_AGAINST", "PYTEST_*" ]
 set_env.COVERAGE_FILE = "{env:COVERAGE_FILE:{toxworkdir}{/}.coverage.{envname}}"
 commands = [