style: fix code formatting and linting issues

- Remove unused imports in stats_client.py and download_stats.py
- Fix import sorting in test files
- Remove unnecessary f-strings in server.py and demo script
- Clean up whitespace and formatting issues
- Ensure all files pass ruff and isort checks

Signed-off-by: longhao <hal.long@outlook.com>

examples/download_stats_demo.py

@@ -7,7 +7,6 @@ to analyze PyPI package popularity and trends.
 """
 
 import asyncio
-import json
 from datetime import datetime
 
 from pypi_query_mcp.tools.download_stats import (
@@ -44,27 +43,27 @@ async def demo_package_download_stats():
             print(f"Summary: {metadata.get('summary', 'No summary available')[:80]}...")
 
             # Display download counts
-            print(f"\nDownload Counts:")
+            print("\nDownload Counts:")
             print(f"  Last Day:   {downloads.get('last_day', 0):,}")
             print(f"  Last Week:  {downloads.get('last_week', 0):,}")
             print(f"  Last Month: {downloads.get('last_month', 0):,}")
 
             # Display analysis
             if analysis:
-                print(f"\nAnalysis:")
+                print("\nAnalysis:")
                 print(f"  Total Downloads: {analysis.get('total_downloads', 0):,}")
                 print(f"  Highest Period: {analysis.get('highest_period', 'N/A')}")
 
                 growth = analysis.get('growth_indicators', {})
                 if growth:
-                    print(f"  Growth Indicators:")
+                    print("  Growth Indicators:")
                     for indicator, value in growth.items():
                         print(f"    {indicator}: {value}")
 
             # Display repository info if available
             project_urls = metadata.get('project_urls', {})
             if project_urls:
-                print(f"\nRepository Links:")
+                print("\nRepository Links:")
                 for name, url in project_urls.items():
                     if url:
                         print(f"  {name}: {url}")
@@ -110,7 +109,7 @@ async def demo_package_download_trends():
 
         # Show recent data points (last 7 days)
         if time_series:
-            print(f"\nRecent Download Data (last 7 days):")
+            print("\nRecent Download Data (last 7 days):")
             recent_data = [item for item in time_series if item.get('category') == 'without_mirrors'][-7:]
             for item in recent_data:
                 date = item.get('date', 'unknown')
@@ -146,7 +145,7 @@ async def demo_top_packages():
             if top_packages.get("note"):
                 print(f"Note: {top_packages['note']}")
 
-            print(f"\nRankings:")
+            print("\nRankings:")
             for package in packages_list:
                 rank = package.get("rank", "?")
                 name = package.get("package", "unknown")
@@ -166,7 +165,7 @@ async def demo_package_comparison():
     # Compare web frameworks
     frameworks = ["django", "flask", "fastapi", "tornado"]
 
-    print(f"\n🔍 Comparing Web Frameworks (last month downloads):")
+    print("\n🔍 Comparing Web Frameworks (last month downloads):")
     print("-" * 70)
 
     comparison_data = []

pypi_query_mcp/core/stats_client.py

@@ -2,7 +2,6 @@
 
 import asyncio
 import logging
-from datetime import datetime, timedelta
 from typing import Any
 
 import httpx

pypi_query_mcp/server.py

@@ -541,7 +541,7 @@ async def get_top_downloaded_packages(
 
         logger.info(f"MCP tool: Getting top {actual_limit} packages for period: {period}")
         result = await get_top_packages_by_downloads(period, actual_limit)
-        logger.info(f"Successfully retrieved top packages list")
+        logger.info("Successfully retrieved top packages list")
         return result
     except Exception as e:
         logger.error(f"Error getting top packages: {e}")

pypi_query_mcp/tools/download_stats.py

@@ -1,12 +1,11 @@
 """PyPI package download statistics tools."""
 
 import logging
-from datetime import datetime, timedelta
+from datetime import datetime
 from typing import Any
 
 from ..core.pypi_client import PyPIClient
 from ..core.stats_client import PyPIStatsClient
-from ..core.exceptions import InvalidPackageNameError, NetworkError, PackageNotFoundError
 
 logger = logging.getLogger(__name__)
 

tests/test_download_stats.py

@@ -1,17 +1,18 @@
 """Tests for download statistics functionality."""
 
-import pytest
 from unittest.mock import AsyncMock, patch
 
+import pytest
+
+from pypi_query_mcp.core.exceptions import PackageNotFoundError
 from pypi_query_mcp.tools.download_stats import (
-    get_package_download_stats,
-    get_package_download_trends,
-    get_top_packages_by_downloads,
     _analyze_download_stats,
     _analyze_download_trends,
     _extract_download_count,
+    get_package_download_stats,
+    get_package_download_trends,
+    get_top_packages_by_downloads,
 )
-from pypi_query_mcp.core.exceptions import PackageNotFoundError, InvalidPackageNameError
 
 
 class TestDownloadStats: