Fix all typing issues

base-notebook/jupyter_notebook_config.py

@@ -1,12 +1,12 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
-
+# mypy: ignore-errors
 from jupyter_core.paths import jupyter_data_dir
 import subprocess
 import os
-import errno
 import stat
 
+
 c = get_config()  # noqa: F821
 c.NotebookApp.ip = "0.0.0.0"
 c.NotebookApp.port = 8888
@@ -16,28 +16,21 @@ c.NotebookApp.open_browser = False
 c.FileContentsManager.delete_to_trash = False
 
 # Generate a self-signed certificate
+OPENSSL_CONFIG = """\
+[req]
+distinguished_name = req_distinguished_name
+[req_distinguished_name]
+"""
 if "GEN_CERT" in os.environ:
     dir_name = jupyter_data_dir()
     pem_file = os.path.join(dir_name, "notebook.pem")
-    try:
-        os.makedirs(dir_name)
-    except OSError as exc:  # Python >2.5
-        if exc.errno == errno.EEXIST and os.path.isdir(dir_name):
-            pass
-        else:
-            raise
+    os.makedirs(dir_name, exist_ok=True)
 
     # Generate an openssl.cnf file to set the distinguished name
     cnf_file = os.path.join(os.getenv("CONDA_DIR", "/usr/lib"), "ssl", "openssl.cnf")
     if not os.path.isfile(cnf_file):
         with open(cnf_file, "w") as fh:
-            fh.write(
-                """\
-[req]
-distinguished_name = req_distinguished_name
-[req_distinguished_name]
-"""
-            )
+            fh.write(OPENSSL_CONFIG)
 
     # Generate a certificate if one doesn't exist on disk
     subprocess.check_call(