Add docstrings to patroni.exceptions (#2703)

patroni/exceptions.py

@@ -1,33 +1,55 @@
+"""Implement high-level Patroni exceptions.
+
+More specific exceptions can be found in other modules, as subclasses of any exception defined in this module.
+"""
 from typing import Any
 
 
 class PatroniException(Exception):
+    """Parent class for all kind of Patroni exceptions.
 
-    """Parent class for all kind of exceptions related to selected distributed configuration store"""
+    :ivar value: description of the exception.
+    """
 
     def __init__(self, value: Any) -> None:
+        """Create a new instance of :class:`PatroniException` with the given description.
+
+        :param value: description of the exception.
+        """
         self.value = value
 
 
 class PatroniFatalException(PatroniException):
+    """Catastrophic exception that prevents Patroni from performing its job."""
+
     pass
 
 
 class PostgresException(PatroniException):
+    """Any exception related with Postgres management."""
+
     pass
 
 
 class DCSError(PatroniException):
+    """Parent class for all kind of DCS related exceptions."""
+
     pass
 
 
 class PostgresConnectionException(PostgresException):
+    """Any problem faced while connecting to a Postgres instance."""
+
     pass
 
 
 class WatchdogError(PatroniException):
+    """Any problem faced while managing a watchdog device."""
+
     pass
 
 
 class ConfigParseError(PatroniException):
+    """Any issue identified while loading or validating the Patroni configuration."""
+
     pass