MCP Python Interpreter

Instructions

List all Python files in a directory.

Args:
    directory_path: Path to directory (empty for working directory)

Implementation Reference

• mcp_python_interpreter/server.py:806-869 (handler)

  The handler function decorated with @mcp.tool() that implements the list_directory tool logic. It lists Python files in the given directory, groups them by subdirectories, and formats the output with sizes.

  @mcp.tool()
  def list_directory(directory_path: str = "") -> str:
      """
      List all Python files in a directory.
      
      Args:
          directory_path: Path to directory (empty for working directory)
      """
      try:
          if not directory_path:
              path = WORKING_DIR
          else:
              path = Path(directory_path)
              if path.is_absolute():
                  if not is_path_allowed(path):
                      return f"Access denied: Can only list files in working directory: {WORKING_DIR}"
              else:
                  path = WORKING_DIR / directory_path
                  
          if not path.exists():
              return f"Error: Directory '{directory_path}' not found"
              
          if not path.is_dir():
              return f"Error: '{directory_path}' is not a directory"
              
          files = find_python_files(path)
          
          if not files:
              return f"No Python files found in {directory_path or 'working directory'}"
              
          result = f"Python files in: {directory_path or str(WORKING_DIR)}\n\n"
          
          files_by_dir = {}
          base_dir = path if ALLOW_SYSTEM_ACCESS else WORKING_DIR
          
          for file in files:
              file_path = Path(file["path"])
              try:
                  relative_path = file_path.relative_to(base_dir)
                  parent = str(relative_path.parent)
                  if parent == ".":
                      parent = "(root)"
              except ValueError:
                  parent = str(file_path.parent)
                  
              if parent not in files_by_dir:
                  files_by_dir[parent] = []
                  
              files_by_dir[parent].append({
                  "name": file["name"],
                  "size": file["size"]
              })
              
          for dir_name, dir_files in sorted(files_by_dir.items()):
              result += f"📁 {dir_name}:\n"
              for file in sorted(dir_files, key=lambda x: x["name"]):
                  size_kb = round(file["size"] / 1024, 1)
                  result += f"  📄 {file['name']} ({size_kb} KB)\n"
              result += "\n"
              
          return result
      except Exception as e:
          return f"Error listing directory: {str(e)}"

• mcp_python_interpreter/server.py:394-410 (helper)

  Helper function used by list_directory to recursively find all Python (*.py) files in a directory and collect their path, name, size, and modification time.

  def find_python_files(directory: Path) -> List[Dict[str, str]]:
      """Find all Python files in a directory."""
      files = []
      
      if not directory.exists():
          return files
      
      for path in directory.rglob("*.py"):
          if path.is_file():
              files.append({
                  "path": str(path),
                  "name": path.name,
                  "size": path.stat().st_size,
                  "modified": path.stat().st_mtime
              })
      
      return files

• mcp_python_interpreter/server.py:806-806 (registration)

  The @mcp.tool() decorator registers the list_directory function as an MCP tool.

  @mcp.tool()