Python 单实例模式 链接到标题 class Singleton(object): _instances = {} def __new__(cls, *args, **kwargs): if cls not in cls._instances: cls._instances[cls] = super(Singleton, cls).__new__(cls, *args, **kwargs) return cls._instances[cls] class MySingleton(Singleton): def __init__(self, val): self.val = val a = MySingleton(1) b = MySingleton(1) print a.val print b.val 二维数组查找 链接到标题 def find_num(matrix, num): if not matrix: return False rows = len(matrix) cols = len(matrix[0]) row, col = rows - 1, 0 while row >= 0 or col <= cols -1: if matrix[row][col] == num: return num elif matrix[row][col] > num: row -= 1 else: col += 1 return False matrix = [[1,2,3,4], [5,6,7,8] ] print find_num(matrix, 7) 打印链表 链接到标题 class Links(self): def __init__(self, x): self.