1. 队列初始化
创建空的队列:
python
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test_list = []
使用初始值:
python
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test_list = [1, 2, 3, 4, 5]
test_list3 = ["a", "b", "c", "d"]
使用列表生成式创建一个带有初始元素的列表:
python
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>>> test_list = [x for x in range(3, 15, 2)]
>>> print(test_list)
[3, 5, 7, 9, 11, 13]
将字典的key转换为队列:
python
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>>> test_dict = {"one":1,"two":2,"three":3}
>>> print(list(test_dict.keys()))
['one', 'two', 'three']
将字典的value都转换为队列:
python
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>>> test_dict = {"one":1,"two":2,"three":3}
>>> print(list(test_dict.values()))
[1, 2, 3]
将字典的key和value都转换为队列:
python
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>>> test_dict = {"one":1,"two":2,"three":3}
>>> print(list(test_dict.items()))
[('one', 1), ('two', 2), ('three', 3)]
2. 判断一个元素是否在队列中:
index函数,返回元素在队列中的位置:
python
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test_list = [1, 2, 3, 4, 5]
try:
print(test_list.index(3))
except Exception as e:
print('队列中不存在!')
count函数,统计元素在队列中的次数:
python
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test_list = [1, 2, 3, 4, 5]
print(test_list.count(3))
通过in来判断:
python
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test_list = [1, 2, 3, 4, 5]
a = 3
if a in test_list :
print("a在队列中")
else:
print("a不在队列中")
3. 向队列中加入新元素:
append函数,在队列尾部追加:
python
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>>> test_list = [1,2,3,4]
>>> test_list.append(5)
>>> test_list.append(6)
>>> test_list.append(7)
>>> print(test_list)
[1, 2, 3, 4, 5, 6, 7]
insert函数,在队列特定位置插入:
python
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>>> test_list = [1,2,3,4]
>>> test_list.insert(2,9)
>>> print(test_list)
[1, 2, 9, 3, 4]
更改队列特定位置的值:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> test_list[3]=7
>>> print(test_list)
[1, 2, 3, 7, 5]
4. 向队列中追加另外一个队列:
extend函数,在队列的末尾追加新队列:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> test_list2 = [6, 7]
>>> test_list.extend(test_list2)
>>> print(test_list)
[1, 2, 3, 4, 5, 6, 7]
将两个队列合并:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> test_list2 = [6, 7]
>>> test_list3 = test_list + test_list2
>>> print(test_list3)
[1, 2, 3, 4, 5, 6, 7]
5. 遍历队列:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> for a in test_list:
... print(a)
...
1
2
3
4
5
反向遍历队列:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> for a in reversed(test_list):
... print(a)
...
5
4
3
2
1
6. 队列排序:
sort(cmp=None, key=None, reverse=False)函数,升序排列:
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.sort()
>>> print(test_list)
[0, 1, 2, 3, 5, 6, 7, 8, 9]
降序排列,使用sort(reverse=True):
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.sort(reverse=True)
>>> print(test_list)
[9, 8, 7, 6, 5, 3, 2, 1, 0]
7. 获取队列长度:
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> len(test_list)
9
8. 获取队列特定位置元素的值:
python
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>>> test_list = [1, 2, 3, 4, 5]
>>> print(test_list[3])
4
9. 删除队列中的元素:
remove函数,删除队列中匹配到某个值的第一个元素
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.remove(2)
>>> print(test_list)
[1, 3, 5, 6, 8, 9, 7, 0]
pop函数,删除队列中指定位置的元素,并返回该元素
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.pop(2)
3
>>> print(test_list)
[2, 1, 5, 6, 8, 9, 7, 0]
pop参数为空时,删除队列中最后一个元素,并返回该元素
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.pop()
0
>>> print(test_list)
[2, 1, 3, 5, 6, 8, 9, 7]
10. 清除队列中的元素:
python
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>>> test_list = [2, 1, 3, 5, 6, 8, 9, 7, 0]
>>> test_list.clear()
>>> print(test_list)
[]