MCP Python Interpreter

Instructions

Execute a Python file (always uses subprocess for file execution).

Args:
    file_path: Path to the Python file to execute
    environment: Name of the Python environment to use
    arguments: List of command-line arguments to pass to the script
    timeout: Maximum execution time in seconds (default: 300)

Implementation Reference

• mcp_python_interpreter/server.py:627-682 (handler)

  The @mcp.tool() decorated function that implements and registers the 'run_python_file' tool. It validates the file path, selects the Python environment, constructs the command with optional arguments, executes the file via subprocess, and formats the output including stdout/stderr and status.

  @mcp.tool()
  async def run_python_file(
      file_path: str,
      environment: str = "default",
      arguments: Optional[List[str]] = None,
      timeout: int = 300
  ) -> str:
      """
      Execute a Python file (always uses subprocess for file execution).
      
      Args:
          file_path: Path to the Python file to execute
          environment: Name of the Python environment to use
          arguments: List of command-line arguments to pass to the script
          timeout: Maximum execution time in seconds (default: 300)
      """
      path = Path(file_path)
      if path.is_absolute():
          if not is_path_allowed(path):
              return f"Access denied: Can only run files in working directory: {WORKING_DIR}"
      else:
          path = WORKING_DIR / path
      
      if not path.exists():
          return f"File '{path}' not found."
      
      environments = get_python_environments()
      
      if environment == "default" and not any(e["name"] == "default" for e in environments):
          environment = "system"
          
      env = next((e for e in environments if e["name"] == environment), None)
      if not env:
          return f"Environment '{environment}' not found. Available: {', '.join(e['name'] for e in environments)}"
      
      cmd = [env["path"], str(path)]
      if arguments:
          cmd.extend(arguments)
      
      result = await run_subprocess_async(cmd, cwd=str(WORKING_DIR), timeout=timeout)
      
      output = f"Execution of '{path}' in '{environment}' environment:\n\n"
      
      if result["status"] == 0:
          output += "--- Output ---\n"
          output += result["stdout"] if result["stdout"] else "(No output)\n"
      else:
          output += f"--- Error (status code: {result['status']}) ---\n"
          output += result["stderr"] if result["stderr"] else "(No error message)\n"
          
          if result["stdout"]:
              output += "\n--- Output ---\n"
              output += result["stdout"]
      
      return output