python中os.path.isabs(path)的分析

这个本身是小组朋友问的问题，感觉不错，我给出的回答 问：

>>> os.path.isabs("/home")
True
>>> os.path.isabs("/home/..")
True
>>> os.path.isabs("home/..")
False

这里第二个应该是相对路径吧？ 应该返回False？

答：

首先，给段资料 The current os.path.isabs documentation says: > isabs(path) >    Return True if path is an absolute pathname (begins with a slash). The "begins with a slash" part is incorrect since certain systems use a different pathname notation. For example, on Macintosh (where os.sep == ":") this is an absolute pathname: hardDriveName:folderName1:folderName2:fileName.ext ...and this is a relative one: :folderName1:fileName.ext Moreover, on Windows os.path.isabs('\\') returns True since '\\' is an alias for the current drive letter (e.g. C:\\) hence, independently from what said before, the documentation should include also the "backslash" term. It turns out that on Windows there are really 4 different kinds of paths: 1) Completely relative, e.g. foo\bar 2) Completely absolute, e.g. c:\foo\bar or \\server\share 3) Halfbreeds with no drive, e.g. \foo\bar 4) Halfbreeds relative to the current working directory on a specific drive, e.g. c:foo\bar Python 2.5's os.path.isabs() method considers both (2) and (3) to be absolute; 然后，分析 |这里第二个应该是相对路径吧？ 应该返回False？ 根据， linux中absolute *is* begins with a slash, so return True 说说，第三个吧，你除非在"/"目录下，要不然在其他目录下当然是错的，应为这个路径就不对 而，我在"/"目录下也试了，也返回False，那是因为没有以slash开始 linux中，你只用记下上面那句话就好，其他系统看上面的资料