add flake8 and mypy settings

.pre-commit-config.yaml

@@ -48,21 +48,27 @@ repos:
       - id: doc8
         args: [--max-line-length=200]
 
-  # - repo: https://github.com/pycqa/flake8
-  #   rev: 4.0.1
-  #   hooks:
-  #     - id: flake8
-  #       additional_dependencies:
-  #         [
-  #           "flake8-bugbear==20.1.4",
-  #           "flake8-logging-format==0.6.0",
-  #           "flake8-implicit-str-concat==0.2.0",
-  #         ]
+  - repo: https://github.com/pycqa/flake8
+    rev: 4.0.1
+    hooks:
+      - id: flake8
+        additional_dependencies:
+          [
+            "flake8-bugbear==20.1.4",
+            "flake8-logging-format==0.6.0",
+            "flake8-implicit-str-concat==0.2.0",
+          ]
 
-  # - repo: https://github.com/pre-commit/mirrors-mypy
-  #   rev: v0.942
-  #   hooks:
-  #     - id: mypy
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v0.942
+    hooks:
+      - id: mypy
+        exclude: |
+          exclude: |
+            (?x)^(
+              jupyter_core/tests/.*_config.py |
+              scripts/jupyter
+            )$
 
   - repo: https://github.com/sirosen/check-jsonschema
     rev: 0.14.2

MANIFEST.in

@@ -2,6 +2,7 @@ include COPYING.md
 include CONTRIBUTING.md
 include README.md
 include dev-requirements.txt
+include jupyter_core/py.typed
 
 exclude .pre-commit-config.yaml
 exclude .git-blame-ignore-revs

docs/conf.py

@@ -208,16 +208,7 @@
 
 # -- Options for LaTeX output ---------------------------------------------
 
-latex_elements = {
-    # The paper size ('letterpaper' or 'a4paper').
-    #'papersize': 'letterpaper',
-    # The font size ('10pt', '11pt' or '12pt').
-    #'pointsize': '10pt',
-    # Additional stuff for the LaTeX preamble.
-    #'preamble': '',
-    # Latex figure (float) alignment
-    #'figure_align': 'htbp',
-}
+latex_elements: dict = {}
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,

jupyter_core/__init__.py

@@ -1 +1 @@
-from .version import __version__, version_info
+from .version import __version__, version_info  # noqa

jupyter_core/command.py

@@ -21,7 +21,7 @@
 
 
 class JupyterParser(argparse.ArgumentParser):
-    @property
+    @property  # type:ignore[override]
     def epilog(self):
         """Add subcommands to epilog on request
 
@@ -30,7 +30,7 @@ def epilog(self):
         return "Available subcommands: %s" % " ".join(list_subcommands())
 
     @epilog.setter
-    def epilog(self, x):
+    def epilog(self):
         """Ignore epilog set in Parser.__init__"""
         pass
 

jupyter_core/paths.py

@@ -17,6 +17,7 @@
 import warnings
 from contextlib import contextmanager
 from pathlib import Path
+from typing import Optional
 
 pjoin = os.path.join
 
@@ -43,7 +44,7 @@ def get_home_dir():
     return homedir
 
 
-_dtemps = {}
+_dtemps: dict = {}
 
 
 def _mkdtemp_once(name):
@@ -159,7 +160,7 @@ def jupyter_path(*subdirs):
     ['~/.local/jupyter/kernels', '/usr/local/share/jupyter/kernels']
     """
 
-    paths = []
+    paths: list = []
 
     # highest priority is explicit environment variable
     if os.environ.get("JUPYTER_PATH"):
@@ -170,13 +171,16 @@ def jupyter_path(*subdirs):
     if site.ENABLE_USER_SITE:
         # Check if site.getuserbase() exists to be compatible with virtualenv,
         # which often does not have this method.
+        userbase: Optional[str]
         if hasattr(site, "getuserbase"):
             userbase = site.getuserbase()
         else:
             userbase = site.USER_BASE
-        userdir = os.path.join(userbase, "share", "jupyter")
-        if userdir not in user:
-            user.append(userdir)
+
+        if userbase:
+            userdir = os.path.join(userbase, "share", "jupyter")
+            if userdir not in user:
+                user.append(userdir)
 
     env = [p for p in ENV_JUPYTER_PATH if p not in SYSTEM_JUPYTER_PATH]
 
@@ -225,7 +229,7 @@ def jupyter_config_path():
         # jupyter_config_dir makes a blank config when JUPYTER_NO_CONFIG is set.
         return [jupyter_config_dir()]
 
-    paths = []
+    paths: list = []
 
     # highest priority is explicit environment variable
     if os.environ.get("JUPYTER_CONFIG_PATH"):
@@ -234,16 +238,18 @@ def jupyter_config_path():
     # Next is environment or user, depending on the JUPYTER_PREFER_ENV_PATH flag
     user = [jupyter_config_dir()]
     if site.ENABLE_USER_SITE:
+        userbase: Optional[str]
         # Check if site.getuserbase() exists to be compatible with virtualenv,
         # which often does not have this method.
         if hasattr(site, "getuserbase"):
             userbase = site.getuserbase()
         else:
             userbase = site.USER_BASE
 
-        userdir = os.path.join(userbase, "etc", "jupyter")
-        if userdir not in user:
-            user.append(userdir)
+        if userbase:
+            userdir = os.path.join(userbase, "etc", "jupyter")
+            if userdir not in user:
+                user.append(userdir)
 
     env = [p for p in ENV_CONFIG_PATH if p not in SYSTEM_CONFIG_PATH]
 
@@ -298,7 +304,7 @@ def is_file_hidden_win(abs_path, stat_res=None):
             raise
 
     try:
-        if stat_res.st_file_attributes & stat.FILE_ATTRIBUTE_HIDDEN:
+        if stat_res.st_file_attributes & stat.FILE_ATTRIBUTE_HIDDEN:  # type:ignore[attr-defined]
             return True
     except AttributeError:
         # allow AttributeError on PyPy for Windows
@@ -470,8 +476,8 @@ def _win32_restrict_file_to_user_ctypes(fname):
     import ctypes
     from ctypes import wintypes
 
-    advapi32 = ctypes.WinDLL("advapi32", use_last_error=True)
-    secur32 = ctypes.WinDLL("secur32", use_last_error=True)
+    advapi32 = ctypes.WinDLL("advapi32", use_last_error=True)  # type:ignore[attr-defined]
+    secur32 = ctypes.WinDLL("secur32", use_last_error=True)  # type:ignore[attr-defined]
 
     NameSamCompatible = 2
     WinBuiltinAdministratorsSid = 26
@@ -520,7 +526,7 @@ class ACL(ctypes.Structure):
 
     def _nonzero_success(result, func, args):
         if not result:
-            raise ctypes.WinError(ctypes.get_last_error())
+            raise ctypes.WinError(ctypes.get_last_error())  # type:ignore[attr-defined]
         return args
 
     secur32.GetUserNameExW.errcheck = _nonzero_success
@@ -627,7 +633,7 @@ def CreateWellKnownSid(WellKnownSidType):
         try:
             advapi32.CreateWellKnownSid(WellKnownSidType, None, pSid, ctypes.byref(cbSid))
         except OSError as e:
-            if e.winerror != ERROR_INSUFFICIENT_BUFFER:
+            if e.winerror != ERROR_INSUFFICIENT_BUFFER:  # type:ignore[attr-defined]
                 raise
             pSid = (ctypes.c_char * cbSid.value)()
             advapi32.CreateWellKnownSid(WellKnownSidType, None, pSid, ctypes.byref(cbSid))
@@ -640,7 +646,7 @@ def GetUserNameEx(NameFormat):
         try:
             secur32.GetUserNameExW(NameFormat, None, nSize)
         except OSError as e:
-            if e.winerror != ERROR_MORE_DATA:
+            if e.winerror != ERROR_MORE_DATA:  # type:ignore[attr-defined]
                 raise
         if not nSize.contents.value:
             return None
@@ -665,7 +671,7 @@ def LookupAccountName(lpSystemName, lpAccountName):
                 ctypes.byref(peUse),
             )
         except OSError as e:
-            if e.winerror != ERROR_INSUFFICIENT_BUFFER:
+            if e.winerror != ERROR_INSUFFICIENT_BUFFER:  # type:ignore[attr-defined]
                 raise
         Sid = ctypes.create_unicode_buffer("", cbSid.value)
         pSid = ctypes.cast(ctypes.pointer(Sid), wintypes.LPVOID)
@@ -680,7 +686,7 @@ def LookupAccountName(lpSystemName, lpAccountName):
             ctypes.byref(peUse),
         )
         if not success:
-            raise ctypes.WinError()
+            raise ctypes.WinError()  # type:ignore[attr-defined]
         return pSid, lpReferencedDomainName.value, peUse.value
 
     def AddAccessAllowedAce(pAcl, dwAceRevision, AccessMask, pSid):
@@ -700,7 +706,7 @@ def GetFileSecurity(lpFileName, RequestedInformation):
                 ctypes.byref(nLength),
             )
         except OSError as e:
-            if e.winerror != ERROR_INSUFFICIENT_BUFFER:
+            if e.winerror != ERROR_INSUFFICIENT_BUFFER:  # type:ignore[attr-defined]
                 raise
         if not nLength.value:
             return None
@@ -750,7 +756,7 @@ def MakeAbsoluteSD(pSelfRelativeSecurityDescriptor):
                 ctypes.byref(lpdwPrimaryGroupSize),
             )
         except OSError as e:
-            if e.winerror != ERROR_INSUFFICIENT_BUFFER:
+            if e.winerror != ERROR_INSUFFICIENT_BUFFER:  # type:ignore[attr-defined]
                 raise
         pAbsoluteSecurityDescriptor = (wintypes.BYTE * lpdwAbsoluteSecurityDescriptorSize.value)()
         pDaclData = (wintypes.BYTE * lpdwDaclSize.value)()
@@ -788,7 +794,7 @@ def MakeSelfRelativeSD(pAbsoluteSecurityDescriptor):
                 ctypes.byref(lpdwBufferLength),
             )
         except OSError as e:
-            if e.winerror != ERROR_INSUFFICIENT_BUFFER:
+            if e.winerror != ERROR_INSUFFICIENT_BUFFER:  # type:ignore[attr-defined]
                 raise
         pSelfRelativeSecurityDescriptor = (wintypes.BYTE * lpdwBufferLength.value)()
         advapi32.MakeSelfRelativeSD(
@@ -907,7 +913,7 @@ def issue_insecure_write_warning():
     def format_warning(msg, *args, **kwargs):
         return str(msg) + "\n"
 
-    warnings.formatwarning = format_warning
+    warnings.formatwarning = format_warning  # type:ignore[assignment]
     warnings.warn(
         "WARNING: Insecure writes have been enabled via environment variable "
         "'JUPYTER_ALLOW_INSECURE_WRITES'! If this is not intended, remove the "

jupyter_core/tests/test_command.py

@@ -9,7 +9,6 @@
 
 import pytest
 
-from jupyter_core import __version__
 from jupyter_core.command import list_subcommands
 from jupyter_core.paths import (
     jupyter_config_dir,
@@ -95,7 +94,7 @@ def test_paths_json():
     output = get_jupyter_output(["--paths", "--json"])
     data = json.loads(output)
     assert sorted(data) == ["config", "data", "runtime"]
-    for key, path in data.items():
+    for _, path in data.items():
         assert isinstance(path, list)
 
 

jupyter_core/tests/test_paths.py

@@ -18,7 +18,6 @@
 
 from jupyter_core import paths
 from jupyter_core.paths import (
-    ENV_JUPYTER_PATH,
     is_file_hidden,
     is_hidden,
     jupyter_config_dir,
@@ -148,12 +147,12 @@ def test_data_dir_darwin():
 @pytest.mark.skipif(sys.platform != "win32", reason="only run on windows")
 def test_data_dir_windows():
     data = jupyter_data_dir()
-    assert data == realpath(pjoin(os.environ.get("APPDATA", None), "jupyter"))
+    assert data == realpath(pjoin(os.environ.get("APPDATA", ""), "jupyter"))
 
     with xdg:
         # windows should ignore xdg
         data = jupyter_data_dir()
-    assert data == realpath(pjoin(os.environ.get("APPDATA", None), "jupyter"))
+    assert data == realpath(pjoin(os.environ.get("APPDATA", ""), "jupyter"))
 
 
 @pytest.mark.skipif(sys.platform == "win32", reason="does not run on windows")
@@ -189,12 +188,12 @@ def test_runtime_dir_darwin():
 @pytest.mark.skipif(sys.platform != "win32", reason="only run on windows")
 def test_runtime_dir_windows():
     runtime = jupyter_runtime_dir()
-    assert runtime == realpath(pjoin(os.environ.get("APPDATA", None), "jupyter", "runtime"))
+    assert runtime == realpath(pjoin(os.environ.get("APPDATA", ""), "jupyter", "runtime"))
 
     with xdg:
         # windows should ignore xdg
         runtime = jupyter_runtime_dir()
-    assert runtime == realpath(pjoin(os.environ.get("APPDATA", None), "jupyter", "runtime"))
+    assert runtime == realpath(pjoin(os.environ.get("APPDATA", ""), "jupyter", "runtime"))
 
 
 @pytest.mark.skipif(sys.platform == "win32", reason="does not run on windows")
@@ -364,7 +363,7 @@ def test_is_hidden():
     reason="only run on windows/cpython or pypy >= 7.3.6: https://foss.heptapod.net/pypy/pypy/-/issues/3469",
 )
 def test_is_hidden_win32_cpython():
-    import ctypes
+    import ctypes  # noqa
 
     with tempfile.TemporaryDirectory() as root:
         subdir1 = os.path.join(root, "subdir")
@@ -384,7 +383,7 @@ def test_is_hidden_win32_cpython():
     reason="only run on windows/pypy < 7.3.6: https://foss.heptapod.net/pypy/pypy/-/issues/3469",
 )
 def test_is_hidden_win32_pypy():
-    import ctypes
+    import ctypes  # noqa
 
     with tempfile.TemporaryDirectory() as root:
         subdir1 = os.path.join(root, "subdir")