Get general stats information.
        
        Includes:
        
        - size_total: total size on disk
        - num_folder_total: how many subfolders
        - num_file_total: how many files
        - size_current: total size of files on this folder. file in subfolders 
            doesn't count
        - num_folder_current: how many files, subfolders doens't count
        - num_file_current: how many files, file in subfolders doens't count

def get_detail(self):
        """Get general stats information.
        
        Includes:
        
        - size_total: total size on disk
        - num_folder_total: how many subfolders
        - num_file_total: how many files
        - size_current: total size of files on this folder. file in subfolders 
            doesn't count
        - num_folder_current: how many files, subfolders doens't count
        - num_file_current: how many files, file in subfolders doens't count
        """
        self.size_total = 0
        self.num_folder_total = 0
        self.num_file_total = 0
        
        self.size_current = 0
        self.num_folder_current = 0
        self.num_file_current = 0
        
        for current_dir, folderlist, fnamelist in os.walk(self.abspath):
            self.num_folder_total += len(folderlist)
            self.num_file_total += len(fnamelist)
            for fname in fnamelist:
                self.size_total += os.path.getsize(os.path.join(current_dir, fname))
                
        current_dir, folderlist, fnamelist = next(os.walk(self.abspath))
        self.num_folder_current = len(folderlist)
        self.num_file_current = len(fnamelist)
        for fname in fnamelist:
            self.size_current += os.path.getsize(os.path.join(current_dir, fname))