Fix broken imports of urllib (#3767)

`import urllib` does not automatically make the `urllib.request`
and `urllib.error` modules available.

aiida/cmdline/commands/cmd_import.py

@@ -11,7 +11,7 @@
 # pylint: disable=broad-except,too-many-arguments,too-many-locals,too-many-branches
 from enum import Enum
 import traceback
-import urllib
+import urllib.request
 import click
 
 from aiida.cmdline.commands.cmd_verdi import verdi

aiida/cmdline/params/types/path.py

@@ -9,7 +9,9 @@
 ###########################################################################
 """Click parameter types for paths."""
 import os
-import urllib
+# See https://stackoverflow.com/a/41217363/1069467
+import urllib.request
+import urllib.error
 
 import click
 
@@ -53,10 +55,11 @@ def __repr__(self):
 class ImportPath(click.Path):
     """AiiDA extension of Click's Path-type to include URLs
     An ImportPath can either be a `click.Path`-type or a URL.
+
     :param timeout_seconds: Timeout time in seconds that a URL response is expected.
     :value timeout_seconds: Must be an int in the range [0;60], extrema included.
-    If an int outside the range [0;60] is given, the value will be set to the respective extremum value.
-    If any other type than int is given a TypeError will be raised.
+      If an int outside the range [0;60] is given, the value will be set to the respective extremum value.
+      If any other type than int is given a TypeError will be raised.
     """
 
     # pylint: disable=protected-access

aiida/manage/configuration/setup.py

@@ -9,7 +9,7 @@
 ###########################################################################
 """Module that defines methods required to setup a new AiiDA instance."""
 import os
-import urllib
+import urllib.parse
 
 import click
 

aiida/restapi/common/utils.py

@@ -8,7 +8,7 @@
 # For further information please visit http://www.aiida.net               #
 ###########################################################################
 """ Util methods """
-import urllib
+import urllib.parse
 from datetime import datetime, timedelta
 
 from flask import jsonify

aiida/tools/importexport/common/utils.py

@@ -10,7 +10,8 @@
 """ Utility functions for import/export of AiiDA entities """
 # pylint: disable=inconsistent-return-statements,too-many-branches,too-many-return-statements
 # pylint: disable=too-many-nested-blocks,too-many-locals
-import urllib
+import urllib.request
+import urllib.parse
 from html.parser import HTMLParser
 
 from aiida.tools.importexport.common.config import (

tests/tools/dbimporters/test_icsd.py

@@ -10,12 +10,10 @@
 """
 Tests for IcsdDbImporter
 """
-import urllib
-
+import urllib.request
 import pytest
 
 from aiida.backends.testbase import AiidaTestCase
-
 from aiida.tools.dbimporters.plugins import icsd