Add and fix more type hints

Summary

Related to #192 (closed)

Adding more type hints to smaller modules than models.py

Focus

Point the reviewer to the core of the code change. Where should they start reading? What should they focus on (e.g. security, performance, maintainability, user-friendliness, compliance with the specs, finding more corner cases, concrete questions)?

Test Environment

How to set up a test environment for manual testing?

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md (or not necessary)
• Up-to-date JSON schema (or not necessary)
• Appropriate user and developer documentation (or not necessary)
  • How do I use the software? Assume "stupid" users.
  • How do I develop or debug the software? Assume novice developers.
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there specifications? Are they satisfied?

For further good practices have a look at our review guidelines.

src/linkahead/configuration.py

@@ -21,14 +21,14 @@
 #
 # ** end header
 #
-
+from __future__ import annotations
 import os
 import warnings
 
 import yaml
 
 try:
-    optional_jsonschema_validate = None
+    optional_jsonschema_validate: Optional[Callable] = None
     from jsonschema import validate as optional_jsonschema_validate
 except ImportError:
     pass
@@ -37,13 +37,15 @@ from configparser import ConfigParser
 from os import environ, getcwd
 from os.path import expanduser, isfile, join
 
+from typing import Dict, Union, Callable, Optional
+
 
 def _reset_config():
     global _pycaosdbconf
     _pycaosdbconf = ConfigParser(allow_no_value=False)
 
 
-def configure(inifile):
+def configure(inifile: str) -> list[str]:
     """read config from file.
 
     Return a list of files which have successfully been parsed.
@@ -61,15 +63,15 @@ def configure(inifile):
     return read_config
 
 
-def get_config():
+def get_config() -> ConfigParser:
     global _pycaosdbconf
     if ("_pycaosdbconf" not in globals() or _pycaosdbconf is None):
         _reset_config()
     return _pycaosdbconf
 
 
-def config_to_yaml(config):
-    valobj = {}
+def config_to_yaml(config: ConfigParser) -> Dict[str, Dict[str, Union[int, str, bool]]]:
+    valobj: Dict[str, Dict[str, Union[int, str, bool]]] = {}
     for s in config.sections():
         valobj[s] = {}
         for key, value in config[s].items():
@@ -84,7 +86,7 @@ def config_to_yaml(config):
     return valobj
 
 
-def validate_yaml_schema(valobj):
+def validate_yaml_schema(valobj: Dict[str, Dict[str, Union[int, str, bool]]]):
     if optional_jsonschema_validate:
         with open(os.path.join(os.path.dirname(__file__), "schema-pycaosdb-ini.yml")) as f:
             schema = yaml.load(f, Loader=yaml.SafeLoader)
@@ -95,7 +97,7 @@ def validate_yaml_schema(valobj):
         """)
 
 
-def _read_config_files():
+def _read_config_files() -> list[str]:
     """Read config files from different paths.
 
     Read the config from either ``$PYCAOSDBINI`` or home directory (``~/.pylinkahead.ini``), and