os.path.join(path, *paths)

• Join one or more path components intelligently. 
• The return value is the concatenation of path and any members of *paths with exactly one directory separator (os.sep) following each non-empty part except the last, meaning that the result will only end in a separator if the last part is empty. 
• If a component is an absolute path, all previous components are thrown away and joining continues from the absolute path component.
• On Windows, the drive letter is not reset when an absolute path component (e.g., r'\foo') is encountered. 
• If a component contains a drive letter, all previous components are thrown away and the drive letter is reset. 
• Note that since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: (c:foo), not c:\foo.

eg:

fileName = os.path.join(dirname, name).replace("\\", "/")