chore: Replace print statements with logging in ADK

Co-authored-by: George Weale <gweale@google.com>
PiperOrigin-RevId: 864588921

src/google/adk/a2a/utils/agent_card_builder.py

@@ -14,6 +14,7 @@
 
 from __future__ import annotations
 
+import logging
 import re
 from typing import Dict
 from typing import List
@@ -33,6 +34,8 @@ from ...agents.sequential_agent import SequentialAgent
 from ...tools.example_tool import ExampleTool
 from ..experimental import a2a_experimental
 
+logger = logging.getLogger('google_adk.' + __name__)
+
 
 @a2a_experimental
 class AgentCardBuilder:
@@ -157,8 +160,8 @@ async def _build_sub_agent_skills(agent: BaseAgent) -> List[AgentSkill]:
         sub_agent_skills.append(aggregated_skill)
     except Exception as e:
       # Log warning but continue with other sub-agents
-      print(
+      logger.warning(
-          f'Warning: Failed to build skills for sub-agent {sub_agent.name}: {e}'
+          'Failed to build skills for sub-agent %s: %s', sub_agent.name, e
       )
       continue
 
@@ -502,7 +505,7 @@ async def _extract_examples_from_agent(
       if isinstance(tool, ExampleTool):
         return _convert_example_tool_examples(tool)
   except Exception as e:
-    print(f'Warning: Failed to extract examples from tools: {e}')
+    logger.warning('Failed to extract examples from tools: %s', e)
 
   # If no example_tool found, try to extract examples from instruction
   if agent.instruction:

src/google/adk/evaluation/evaluation_generator.py

@@ -16,6 +16,7 @@ from __future__ import annotations
 
 import copy
 import importlib
+import logging
 from typing import Any
 from typing import AsyncGenerator
 from typing import Optional
@@ -49,6 +50,8 @@ from .simulation.user_simulator import Status as UserSimulatorStatus
 from .simulation.user_simulator import UserSimulator
 from .simulation.user_simulator_provider import UserSimulatorProvider
 
+logger = logging.getLogger("google_adk." + __name__)
+
 _USER_AUTHOR = "user"
 _DEFAULT_AUTHOR = "agent"
 
@@ -117,7 +120,7 @@ class EvaluationGenerator:
 
     with open(session_path, "r") as f:
       session_data = Session.model_validate_json(f.read())
-      print("loaded session", session_path)
+      logger.info("Loaded session %s", session_path)
 
     for data in eval_dataset:
       # load session data from session_path

src/google/adk/tools/bigtable/query_tool.py

@@ -16,6 +16,7 @@ from __future__ import annotations
 
 """Tool to execute SQL queries against Bigtable."""
 import json
+import logging
 from typing import Any
 from typing import Dict
 from typing import List
@@ -27,6 +28,8 @@ from . import client
 from ..tool_context import ToolContext
 from .settings import BigtableToolSettings
 
+logger = logging.getLogger("google_adk." + __name__)
+
 DEFAULT_MAX_EXECUTED_QUERY_RESULT_ROWS = 50
 
 
@@ -112,7 +115,7 @@ def execute_sql(
     return result
 
   except Exception as ex:
-    print(ex)
+    logger.error("Bigtable query failed: %s", ex)
     return {
         "status": "ERROR",
         "error_details": str(ex),