def trim(a): if len(a) == 0: return a while a[0] == ' ': if len(a) == 1: if a[0] == ' ': a = '' return a break else: break a = a[:] else: a = a[1:] if a[-1] == ' ': while a[-1] == ' ': if len(a) == 1: break a = a[:-1] return a