REFACTOR-#4629: Add type annotations to modin/config (#4685)

Signed-off-by: Karthik Velayutham <vkarthik@ponder.io>

docs/release_notes/release_notes-0.16.0.rst

@@ -36,6 +36,7 @@ Key Features and Updates
   * REFACTOR-#4530: Standardize access to physical data in partitions (#4563)
   * REFACTOR-#4534: Replace logging meta class with class decorator (#4535)
   * REFACTOR-#4708: Delete combine dtypes (#4709)
+  * REFACTOR-#4629: Add type annotations to modin/config (#4685)
 * Pandas API implementations and improvements
   * FEAT-#4670: Implement convert_dtypes by mapping across partitions (#4671)
 * OmniSci enhancements

modin/config/__main__.py

@@ -27,15 +27,15 @@
 import argparse
 
 
-def print_config_help():
+def print_config_help() -> None:
     """Print configs help messages."""
     for objname in sorted(globals()):
         obj = globals()[objname]
         if isinstance(obj, type) and issubclass(obj, Parameter) and not obj.is_abstract:
             print(f"{obj.get_help()}\n\tCurrent value: {obj.get()}")  # noqa: T201
 
 
-def export_config_help(filename: str):
+def export_config_help(filename: str) -> None:
     """
     Export all configs help messages to the CSV file.
 
@@ -57,7 +57,9 @@ def export_config_help(filename: str):
                 if obj.__name__ != "RayRedisPassword"
                 else "random string",
                 # `Notes` `-` underlining can't be correctly parsed inside csv table by sphinx
-                "Description": dedent(obj.__doc__).replace("Notes\n-----", "Notes:\n"),
+                "Description": dedent(obj.__doc__ or "").replace(
+                    "Notes\n-----", "Notes:\n"
+                ),
                 "Options": obj.choices,
             }
             configs_data.append(data)

modin/config/envvars.py

@@ -21,12 +21,13 @@
 import secrets
 
 from .pubsub import Parameter, _TYPE_PARAMS, ExactStr, ValueSource
+from typing import Optional
 
 
 class EnvironmentVariable(Parameter, type=str, abstract=True):
     """Base class for environment variables-based configuration."""
 
-    varname: str = None
+    varname: Optional[str] = None
 
     @classmethod
     def _get_raw_from_config(cls) -> str:
@@ -40,9 +41,13 @@ def _get_raw_from_config(cls) -> str:
 
         Raises
         ------
+        TypeError
+            If `varname` is None.
         KeyError
             If value is absent.
         """
+        if cls.varname is None:
+            raise TypeError("varname should not be None")
         return os.environ[cls.varname]
 
     @classmethod
@@ -73,7 +78,7 @@ class Engine(EnvironmentVariable, type=str):
     choices = ("Ray", "Dask", "Python", "Native")
 
     @classmethod
-    def _get_default(cls):
+    def _get_default(cls) -> str:
         """
         Get default value of the config.
 
@@ -170,7 +175,7 @@ class CpuCount(EnvironmentVariable, type=int):
     varname = "MODIN_CPUS"
 
     @classmethod
-    def _get_default(cls):
+    def _get_default(cls) -> int:
         """
         Get default value of the config.
 
@@ -208,7 +213,7 @@ class NPartitions(EnvironmentVariable, type=int):
     varname = "MODIN_NPARTITIONS"
 
     @classmethod
-    def _put(cls, value):
+    def _put(cls, value: int) -> None:
         """
         Put specific value if NPartitions wasn't set by a user yet.
 
@@ -226,7 +231,7 @@ def _put(cls, value):
             cls.put(value)
 
     @classmethod
-    def _get_default(cls):
+    def _get_default(cls) -> int:
         """
         Get default value of the config.
 
@@ -318,17 +323,17 @@ class ProgressBar(EnvironmentVariable, type=bool):
     default = False
 
     @classmethod
-    def enable(cls):
+    def enable(cls) -> None:
         """Enable ``ProgressBar`` feature."""
         cls.put(True)
 
     @classmethod
-    def disable(cls):
+    def disable(cls) -> None:
         """Disable ``ProgressBar`` feature."""
         cls.put(False)
 
     @classmethod
-    def put(cls, value):
+    def put(cls, value: bool) -> None:
         """
         Set ``ProgressBar`` value only if synchronous benchmarking is disabled.
 
@@ -349,7 +354,7 @@ class BenchmarkMode(EnvironmentVariable, type=bool):
     default = False
 
     @classmethod
-    def put(cls, value):
+    def put(cls, value: bool) -> None:
         """
         Set ``BenchmarkMode`` value only if progress bar feature is disabled.
 
@@ -371,17 +376,17 @@ class LogMode(EnvironmentVariable, type=ExactStr):
     default = "disable"
 
     @classmethod
-    def enable(cls):
+    def enable(cls) -> None:
         """Enable all logging levels."""
         cls.put("enable")
 
     @classmethod
-    def disable(cls):
+    def disable(cls) -> None:
         """Disable logging feature."""
         cls.put("disable")
 
     @classmethod
-    def enable_api_only(cls):
+    def enable_api_only(cls) -> None:
         """Enable API level logging."""
         cls.put("enable_api_only")
 
@@ -393,7 +398,7 @@ class LogMemoryInterval(EnvironmentVariable, type=int):
     default = 5
 
     @classmethod
-    def put(cls, value):
+    def put(cls, value: int) -> None:
         """
         Set ``LogMemoryInterval`` with extra checks.
 
@@ -427,7 +432,7 @@ class LogFileSize(EnvironmentVariable, type=int):
     default = 10
 
     @classmethod
-    def put(cls, value):
+    def put(cls, value: int) -> None:
         """
         Set ``LogFileSize`` with extra checks.
 
@@ -484,7 +489,7 @@ class OmnisciLaunchParameters(EnvironmentVariable, type=dict):
     }
 
     @classmethod
-    def get(self):
+    def get(self) -> dict:
         """
         Get the resulted command-line options.
 
@@ -515,7 +520,7 @@ class MinPartitionSize(EnvironmentVariable, type=int):
     default = 32
 
     @classmethod
-    def put(cls, value):
+    def put(cls, value: int) -> None:
         """
         Set ``MinPartitionSize`` with extra checks.
 
@@ -529,7 +534,7 @@ def put(cls, value):
         super().put(value)
 
     @classmethod
-    def get(cls):
+    def get(cls) -> int:
         """
         Get ``MinPartitionSize`` with extra checks.
 
@@ -564,7 +569,7 @@ class ReadSqlEngine(EnvironmentVariable, type=str):
     choices = ("Pandas", "Connectorx")
 
 
-def _check_vars():
+def _check_vars() -> None:
     """
     Check validity of environment variables.