記錄下os庫中幾個方法
os.curdir
The constant string used by the operating system to refer to the current directory. This is '.' for Windows and POSIX. Also available viaos.path
文檔中原文如上确沸，大致翻譯如下：
常量字符串os.curdir被用來獲取當(dāng)前的目錄缨恒。
os.sep
The character used by the operating system to separate pathname components. This is '/' for POSIX and '\\' for Windows. Note that knowing this is not sufficient to be able to parse or concatenate pathnames — use os.path.split() and os.path.join() — but it is occasionally useful. Also available via os.path
拼接路徑中的符號
