python基础:deque的详细使用(适合在列表两端进行操作元素)
创建双向队列
import collections d = collections.deque()
append(往右边添加一个元素)
import collections d = collections.deque() d.append(1) d.append(2) print(d) #输出:deque([1, 2])
appendleft(往左边添加一个元素)
import collections d = collections.deque() d.append(1) d.appendleft(2) print(d) #输出:deque([2, 1])
clear(清空队列)
import collections d = collections.deque() d.append(1) d.clear() print(d) #输出:deque([])
copy(浅拷贝)
import collections d = collections.deque() d.append(1) new_d = d.copy() print(new_d) #输出:deque([1])
count(返回指定元素的出现次数)
import collections d = collections.deque() d.append(1) d.append(1) print(d.count(1)) #输出:2
extend(从队列右边扩展一个列表的元素)
import collections d = collections.deque() d.append(1) d.extend([3,4,5]) print(d) #输出:deque([1, 3, 4, 5])
extendleft(从队列左边扩展一个列表的元素)
import collections d = collections.deque() d.append(1) d.extendleft([3,4,5]) print(d) # # #输出:deque([5, 4, 3, 1])
index(查找某个元素的索引位置)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) print(d) print(d.index('e')) print(d.index('c',0,3)) #指定查找区间 #输出:deque(['a', 'b', 'c', 'd', 'e']) # 4 # 2
insert(在指定位置插入元素)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) d.insert(2,'z') print(d) #输出:deque(['a', 'b', 'z', 'c', 'd', 'e'])
pop(获取最右边一个元素,并在队列中删除)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) x = d.pop() print(x,d) #输出:e deque(['a', 'b', 'c', 'd'])
popleft(获取最左边一个元素,并在队列中删除)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) x = d.popleft() print(x,d) #输出:a deque(['b', 'c', 'd', 'e'])
remove(删除指定元素)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) d.remove('c') print(d) #输出:deque(['a', 'b', 'd', 'e'])
reverse(队列反转)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) d.reverse() print(d) #输出:deque(['e', 'd', 'c', 'b', 'a'])
rotate(把右边元素放到左边)
import collections d = collections.deque() d.extend(['a','b','c','d','e']) d.rotate(2) #指定次数,默认1次 print(d) #输出:deque(['d', 'e', 'a', 'b', 'c'])