Fix linter issues in consumer testing code (#2051)

Author: fangnx

tests/ducktape/consumer_benchmark_metrics.py

@@ -132,10 +132,10 @@ def get_summary(self) -> Dict[str, Any]:
 
  # Operation metrics (generic for poll/consume)
  operation_error_rate = (self.operation_errors / self.operation_attempts
- if self.operation_attempts > 0 else 0)
- operation_success_rate = ((self.operation_attempts - self.operation_timeouts -
- self.operation_errors) / self.operation_attempts
  if self.operation_attempts > 0 else 0)
+ operation_success_rate = ((self.operation_attempts - self.operation_timeouts -
+ self.operation_errors) / self.operation_attempts
+ if self.operation_attempts > 0 else 0)
 
  # Operation latency analysis
  if self.operation_latencies:
@@ -282,12 +282,12 @@ def validate_consumer_metrics(metrics: Dict[str, Any], bounds: ConsumerMetricsBo
  messages_per_consume = metrics.get('messages_per_consume', 0)
  if messages_per_consume < bounds.min_messages_per_consume:
  violations.append(f"Messages per consume {messages_per_consume:.2f} "
- f"below minimum {bounds.min_messages_per_consume}")
+  f"below minimum {bounds.min_messages_per_consume}")
 
  empty_consume_rate = metrics.get('empty_consume_rate', 0)
  if empty_consume_rate > bounds.max_empty_consume_rate:
  violations.append(f"Empty consume rate {empty_consume_rate:.3f} "
- f"exceeds maximum {bounds.max_empty_consume_rate}")
+  f"exceeds maximum {bounds.max_empty_consume_rate}")
 
  # For poll operations, we skip batch efficiency validation since they're single-message operations
  is_valid = len(violations) == 0

tests/ducktape/test_consumer.py

@@ -9,7 +9,7 @@
 
 from tests.ducktape.services.kafka import KafkaClient
 from tests.ducktape.consumer_benchmark_metrics import (ConsumerMetricsCollector, ConsumerMetricsBounds,
- validate_consumer_metrics, print_consumer_metrics_report)
+  validate_consumer_metrics, print_consumer_metrics_report)
 from tests.ducktape.consumer_strategy import SyncConsumerStrategy, AsyncConsumerStrategy
 from confluent_kafka import Producer