Sorting files on the basis of date modified

last_modified.py

def latest_post():
    """
    returns the last modified post in posts directory 
    """
    
    posts_dic = dict()
    for dirpath, dirnames, filenames in os.walk(posts_directory):
        for dirname in dirnames:
            posts_dic[dirname] = os.stat(dirpath+"/"+dirname).st_mtime
            
        return max(posts_dic.keys(), key=(lambda x: posts_dic[x]))