When running Claude Code when attempting to use the discovered tools (application-info for example) it receives "Invalid JSON output from tool process: Syntax error ...

This phenomenon was originally discovered by @dmarteau in #19892. I wrote and ran the following two tests under Python 3.12 and mypy master (1.19.0+dev) and they succeeded.

If you receive Invalid file handle error during rename, delete, copy, etc. operations in Windows 11/10/8/7, here is a simple solution that will fix your problem ...

Python 3.14通过延迟类型注解、模板字符串、多解释器等特性，在性能、安全性和开发体验方面都实现了显著提升。这些改进使得Python在现代应用开发中更具竞争力，特别是对于Web服务、数据分析和科学计算等场景。