Create a new FileCollection and add all files from ``dir_path``.
        
        :param list_of_dir: absolute dir path, WinDir instance, list of 
          absolute dir path or list of WinDir instance.
          
        **中文文档**
        
        添加dir_path目录下的所有文件到一个新的FileCollection中.

def from_path(list_of_dir):
        """Create a new FileCollection and add all files from ``dir_path``.
        
        :param list_of_dir: absolute dir path, WinDir instance, list of 
          absolute dir path or list of WinDir instance.
          
        **中文文档**
        
        添加dir_path目录下的所有文件到一个新的FileCollection中.
        """
        if isinstance(list_of_dir, str):
            list_of_dir = [list_of_dir, ]
        elif isinstance(list_of_dir, WinDir):
            list_of_dir = [list_of_dir.abspath, ]
        elif isinstance(list_of_dir, list):
            list_of_dir = [str(i) for i in list_of_dir]
            
        fc = FileCollection()
        for dir_path in list_of_dir:
            for winfile in FileCollection.yield_all_winfile(dir_path):
                fc.files.setdefault(winfile.abspath, winfile)
        return fc