Godot文件的读写，运行后会出现a.txt

参照了： https://blog.csdn.net/ttm2d/article/details/103575079?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522165629188516781667813286%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fall.%2522%257D&request_id=165629188516781667813286&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~all~first_rank_ecpm_v1~rank_v31_ecpm-18-103575079-null-null.142^v24^huaweicloudv2,157^v15^new_3&utm_term=Godot+File&spm=1018.2226.3001.4187 这篇文章，以供参考。若有需要，可以看看这篇文章。（网上的其它文章都不是那么易懂）