数据结构(Python版)

求表长

def __iter__(self):
    p=self.head
    while p is not None: # 遍历
        yield p
        p=p.next
def __len__(self):
    cnt=0
    for p in self:
        cnt+=1
    return cnt - 1

判断表是否为空 Head--->罒

def list_empty(self):
    # 若是空表，则返回True。否则返回False
    if self.head.next is not None: # 非空
        return False
    else:
        return True