import time: lazify imports enough that markdown_it isnt imported

pyproject.toml

@@ -160,7 +160,7 @@ commands = [
 description = "Measure module import times. Tox sends mdformat output to stderr, so to filter use e.g. `tox -e benchmark-import 2> >(grep mdformat)`."
 deps = []
 commands = [
-    ["python", "-X", "importtime", "-m", "mdformat"],
+    ["python", "-X", "importtime", "-m", "mdformat", "--version"],
 ]
 
 

src/mdformat/_api.py

@@ -8,7 +8,6 @@
 
 from mdformat._conf import DEFAULT_OPTS
 from mdformat._util import EMPTY_MAP, NULL_CTX, build_mdit, detect_newline_type
-from mdformat.renderer import MDRenderer
 
 
 def text(
@@ -21,6 +20,9 @@ def text(
     _filename: str = "",
 ) -> str:
     """Format a Markdown string."""
+    # Lazy import to improve module import time
+    from mdformat.renderer import MDRenderer
+
     with _first_pass_contextmanager:
         mdit = build_mdit(
             MDRenderer,

src/mdformat/_cli.py

@@ -15,7 +15,6 @@
 from mdformat._conf import DEFAULT_OPTS, InvalidConfError, read_toml_opts
 from mdformat._util import detect_newline_type, is_md_equal
 import mdformat.plugins
-import mdformat.renderer
 
 
 class RendererWarningPrinter(logging.Handler):
@@ -127,13 +126,16 @@ def run(cli_args: Sequence[str], cache_toml: bool = True) -> int:  # noqa: C901
             path_str = "-"
             original_str = sys.stdin.read()
 
+        # Lazy import to improve module import time
+        from mdformat.renderer import LOGGER as RENDERER_LOGGER
+
         formatted_str = mdformat.text(
             original_str,
             options=opts,
             extensions=enabled_parserplugins,
             codeformatters=enabled_codeformatters,
             _first_pass_contextmanager=log_handler_applied(
-                mdformat.renderer.LOGGER, renderer_warning_printer
+                RENDERER_LOGGER, renderer_warning_printer
             ),
             _filename=path_str,
         )

src/mdformat/_util.py

@@ -4,13 +4,13 @@
 from contextlib import nullcontext
 import re
 from types import MappingProxyType
-from typing import Any, Literal
-
-from markdown_it import MarkdownIt
-from markdown_it.renderer import RendererHTML
+from typing import TYPE_CHECKING, Any, Literal
 
 import mdformat.plugins
 
+if TYPE_CHECKING:
+    from markdown_it import MarkdownIt
+
 NULL_CTX = nullcontext()
 EMPTY_MAP: MappingProxyType = MappingProxyType({})
 
@@ -26,6 +26,9 @@ def build_mdit(
     extensions: Iterable[str] = (),
     codeformatters: Iterable[str] = (),
 ) -> MarkdownIt:
+    # Lazy import to improve module import time
+    from markdown_it import MarkdownIt
+
     mdit = MarkdownIt(renderer_cls=renderer_cls)
     mdit.options["mdformat"] = mdformat_opts
     # store reference labels in link/image tokens
@@ -69,6 +72,9 @@ def is_md_equal(
     not a perfect solution, as there can be meaningful whitespace in
     HTML, e.g. in a <code> block.
     """
+    # Lazy import to improve module import time
+    from markdown_it.renderer import RendererHTML
+
     html_texts = {}
     mdit = build_mdit(RendererHTML, mdformat_opts=options, extensions=extensions)
     for key, text in [("md1", md1), ("md2", md2)]: