Use the standard lib tomllib or default to tomli

Following JupyterLab

CHANGELOG.md

@@ -6,6 +6,7 @@ Jupytext ChangeLog
 
 **Changed**
 - Temporary text notebooks for the `--pipe` or `--check` commands are now created in the notebook directory ([#1206](https://github.com/mwouts/jupytext/issues/1206))
+- Jupytext uses the standard library `tomllib` in Python 3.11, or `tomli` in Python 3.10 or older, to match JupyterLab's dependencies ([#1195](https://github.com/mwouts/jupytext/issues/1195))
 
 **Fixed**
 - Jupytext is now tested with `pandoc>=3.0`. Please note that switching to `pandoc>=3.0` will add cell ids to your `pandoc:md` notebooks ([#1006](https://github.com/mwouts/jupytext/issues/1006))

pyproject.toml

@@ -36,7 +36,7 @@ dependencies = [
     "markdown-it-py>=1.0",
     "packaging",
     "pyyaml",
-    "toml",
+    "tomli;python_version<\"3.11\"",
 ]
 dynamic = ["version"]
 

src/jupytext/config.py

@@ -1,6 +1,12 @@
 """Find and read Jupytext configuration files"""
 import json
 import os
+
+try:
+    import tomllib
+except ImportError:
+    import tomli as tomllib
+
 import warnings
 
 import yaml
@@ -334,10 +340,8 @@ def find_jupytext_configuration_file(path, search_parent_dirs=True):
 
     pyproject_path = os.path.join(path, PYPROJECT_FILE)
     if os.path.isfile(pyproject_path):
-        import toml
-
         with open(pyproject_path) as stream:
-            doc = toml.loads(stream.read())
+            doc = tomllib.loads(stream.read())
             if doc.get("tool", {}).get("jupytext") is not None:
                 return pyproject_path
 
@@ -366,9 +370,7 @@ def parse_jupytext_configuration_file(jupytext_config_file, stream=None):
 
     try:
         if jupytext_config_file.endswith((".toml", "jupytext")):
-            import toml
-
-            doc = toml.loads(stream)
+            doc = tomllib.loads(stream)
             if jupytext_config_file.endswith(PYPROJECT_FILE):
                 return doc["tool"]["jupytext"]
             else:

src/jupytext/contentsmanager.py

@@ -2,6 +2,12 @@
 """
 import itertools
 import os
+
+try:
+    import tomllib
+except ImportError:
+    import tomli as tomllib
+
 from collections import namedtuple
 from datetime import timedelta
 
@@ -512,12 +518,10 @@ def get_config_file(self, directory):
 
             pyproject_path = directory + "/" + PYPROJECT_FILE
             if self.file_exists(pyproject_path):
-                import toml
-
                 model = self.get(pyproject_path, type="file")
                 try:
-                    doc = toml.loads(model["content"])
-                except toml.decoder.TomlDecodeError as e:
+                    doc = tomllib.loads(model["content"])
+                except tomllib.TOMLDecodeError as e:
                     self.log.warning(f"Cannot load {pyproject_path}: {e}")
                 else:
                     if doc.get("tool", {}).get("jupytext") is not None: