Use jinja2 FileSystemLoader instead of PackageLoader for compat newer meson-python and editable installs (#62123)

Author: jorisvandenbossche

pandas/io/formats/style_render.py

@@ -6,6 +6,7 @@
     Sequence,
 )
 from functools import partial
+import pathlib
 import re
 from typing import (
     TYPE_CHECKING,
@@ -70,7 +71,9 @@ class StylerRenderer:
     Base class to process rendering a Styler with a specified jinja2 template.
     """
 
-    loader = jinja2.PackageLoader("pandas", "io/formats/templates")
+    this_dir = pathlib.Path(__file__).parent.resolve()
+    template_dir = this_dir / "templates"
+    loader = jinja2.FileSystemLoader(template_dir)
     env = jinja2.Environment(loader=loader, trim_blocks=True)
     template_html = env.get_template("html.tpl")
     template_html_table = env.get_template("html_table.tpl")

pandas/tests/io/formats/style/test_html.py

@@ -1,3 +1,4 @@
+import pathlib
 from textwrap import (
     dedent,
     indent,
@@ -18,7 +19,9 @@
 
 @pytest.fixture
 def env():
-    loader = jinja2.PackageLoader("pandas", "io/formats/templates")
+    project_dir = pathlib.Path(__file__).parent.parent.parent.parent.parent.resolve()
+    template_dir = project_dir / "io" / "formats" / "templates"
+    loader = jinja2.FileSystemLoader(template_dir)
     env = jinja2.Environment(loader=loader, trim_blocks=True)
     return env