Use custom package metadata for augmenting Jupyter paths.

This does not require packages to be imported in order to get the Jupyter paths, which are potentially costly steps. Instead, we rely strictly on scanning and getting package metadata.

examples/jupyter_path_entrypoint_setuptools/setup.cfg

@@ -25,9 +25,17 @@ include_package_data = True
 zip_safe = False
 python_requires = >=3.6
 
+setup_requires =
+    jupyter_core
 install_requires =
     jupyter_core
 
+# Jupyter directories are relative to the package root
+jupyter_config_paths =
+    etc/jupyter
+    etc/another/jupyter
+jupyter_data_paths = share/jupyter
+
 [options.packages.find]
 where =
     src

examples/jupyter_path_entrypoint_setuptools/src/entry_point_example_setuptools/__init__.py

@@ -3,7 +3,7 @@
 
 __version__ = "0.1.0"
 
-HERE = os.path.abspath(os.path.dirname(__file__))
+# HERE = os.path.abspath(os.path.dirname(__file__))
 
-JUPYTER_CONFIG_PATHS = [os.path.join(HERE, "etc", "jupyter")]
-JUPYTER_DATA_PATHS = [os.path.join(HERE, "share", "jupyter")]
+# JUPYTER_CONFIG_PATHS = [os.path.join(HERE, "etc", "jupyter")]
+# JUPYTER_DATA_PATHS = [os.path.join(HERE, "share", "jupyter")]

jupyter_core/paths.py

@@ -19,6 +19,7 @@
 from contextlib import contextmanager
 
 import entrypoints
+import pkg_resources
 
 
 pjoin = os.path.join
@@ -49,6 +50,18 @@ def _entry_point_paths(ep_group):
             ))
     return paths
 
+def _package_metadata(group):
+    """Load extra jupyter paths from custom package metadata
+    """
+    paths = []
+    filename = f'{group}.txt'
+    for distribution in sorted(pkg_resources.working_set, key=lambda x: x.key):
+        if distribution.has_metadata(filename) and distribution.has_metadata('top_level.txt'):
+            top_level = list(distribution.get_metadata_lines('top_level.txt'))[0]
+            localpaths = [f'{top_level}/{p}' for p in distribution.get_metadata_lines(filename)]
+            paths.extend(distribution.get_resource_filename(distribution, p) for p in localpaths if distribution.resource_isdir(p))
+    return paths
+
 def envset(name):
     """Return True if the given environment variable is set
 
@@ -187,16 +200,19 @@ def jupyter_path(*subdirs):
     # Next is environment or user, depending on the JUPYTER_PREFER_ENV_PATH flag
     user = jupyter_data_dir()
     env = [p for p in ENV_JUPYTER_PATH if p not in SYSTEM_JUPYTER_PATH]
-    entry_points = [p for p in _entry_point_paths(JUPYTER_DATA_PATH_ENTRY_POINT) if p not in SYSTEM_JUPYTER_PATH]
+    # entry_points = [p for p in _entry_point_paths(JUPYTER_DATA_PATH_ENTRY_POINT) if p not in SYSTEM_JUPYTER_PATH]
+    package_metadata = [p for p in _package_metadata(JUPYTER_DATA_PATH_ENTRY_POINT) if p not in SYSTEM_JUPYTER_PATH]
 
     if envset('JUPYTER_PREFER_ENV_PATH'):
         paths.extend(env)
-        paths.extend(entry_points)
+        # paths.extend(entry_points)
+        paths.extend(package_metadata)
         paths.append(user)
     else:
         paths.append(user)
         paths.extend(env)
-        paths.extend(entry_points)
+        # paths.extend(entry_points)
+        paths.extend(package_metadata)
 
     # finally, system
     paths.extend(SYSTEM_JUPYTER_PATH)
@@ -244,16 +260,19 @@ def jupyter_config_path():
     # Next is environment or user, depending on the JUPYTER_PREFER_ENV_PATH flag
     user = jupyter_config_dir()
     env = [p for p in ENV_CONFIG_PATH if p not in SYSTEM_CONFIG_PATH]
-    entry_points = [p for p in _entry_point_paths(JUPYTER_CONFIG_PATH_ENTRY_POINT) if p not in SYSTEM_CONFIG_PATH]
+    # entry_points = [p for p in _entry_point_paths(JUPYTER_CONFIG_PATH_ENTRY_POINT) if p not in SYSTEM_CONFIG_PATH]
+    package_metadata = [p for p in _package_metadata(JUPYTER_CONFIG_PATH_ENTRY_POINT) if p not in SYSTEM_CONFIG_PATH]
 
     if envset('JUPYTER_PREFER_ENV_PATH'):
         paths.extend(env)
-        paths.extend(entry_points)
+        # paths.extend(entry_points)
+        paths.extend(package_metadata)
         paths.append(user)
     else:
         paths.append(user)
         paths.extend(env)
-        paths.extend(entry_points)
+        # paths.extend(entry_points)
+        paths.extend(package_metadata)
 
     # Finally, system path
     paths.extend(SYSTEM_CONFIG_PATH)

jupyter_core/utils/__init__.py

@@ -13,4 +13,29 @@ def ensure_dir_exists(path, mode=0o777):
         if e.errno != errno.EEXIST:
             raise
     if not os.path.isdir(path):
-        raise IOError("%r exists but is not a directory" % path)
+        raise IOError("%r exists but is not a directory" % path)
+
+# from setuptools.config.ConfigHandler
+def _parse_list(value, separator=','):
+    """Represents value as a list.
+    Value is split either by separator (defaults to comma) or by lines.
+    :param value:
+    :param separator: List items separator character.
+    :rtype: list
+    """
+    if isinstance(value, list):  # _get_parser_compound case
+        return value
+
+    if '\n' in value:
+        value = value.splitlines()
+    else:
+        value = value.split(separator)
+
+    return [chunk.strip() for chunk in value if chunk.strip()]
+
+def write_arg_list(cmd, basename, filename):
+    argname = os.path.splitext(basename)[0]
+    value = getattr(cmd.distribution, argname, None)
+    if value is not None:
+        value = "\n".join(_parse_list(value)) + "\n"
+    cmd.write_or_delete_file(argname, filename, value)

setup.cfg

@@ -38,3 +38,9 @@ console_scripts =
     jupyter              = jupyter_core.command:main
     jupyter-migrate      = jupyter_core.migrate:main
     jupyter-troubleshoot = jupyter_core.troubleshoot:main
+distutils.setup_keywords =
+    jupyter_config_paths = setuptools.dist:assert_string_list
+    jupyter_data_paths = setuptools.dist:assert_string_list
+egg_info.writers =
+    jupyter_config_paths.txt = jupyter_core.utils:write_arg_list
+    jupyter_data_paths.txt = jupyter_core.utils:write_arg_list