Python排序容器 |一个介绍

Sorted Containers是一个 Apache2 许可的排序集合库，用纯 Python 编写，和 C 扩展一样快。它由 Grant Jenks 创建，是一个开源库。它是容器的集合，允许我们非常有效地插入和删除元素，同时保持排序顺序。

特征：

纯 Python
完整记录
基准比较（替代方案、运行时、负载因子
性能（通常比 C 实现更快）
兼容的 API（几乎与流行的 blist 和 rbtree 模块相同）
功能丰富（例如，获取排序字典中最大的五个键：d.iloc[-5:]）
务实的设计（例如，SortedSet 是一个带有 SortedList 索引的Python集）

容器：

排序列表
排序字典
排序集

安装：

Mac和Linux用户可以通过 pip 命令安装：

sudo pip install sortedcontainers

排序列表 –

排序列表是排序的可变序列，其中值按排序顺序维护。

添加和删除元素的功能：

add(value) : A function that takes one element as parameter and inserts it into the list by maintaining sorted order. Runtime Complexity: O(log(n))

update(iterable): A function that takes an iterable as input and updates the SortedList adding all the values from the iterable Runtime complexity: O(k*log(n)).

clear(): Remove all values from sorted list. Runtime complexity: O(n).

discard(value): Remove value from sorted list if it is a member. If value is not a member, do nothing. Runtime complexity: O(log(n)).

编程需要懂一点英语

下面是实现——

# importing libraries
from sortedcontainers import SortedList, SortedSet, SortedDict
  
# initializing a sorted list with parameters
# it takes an iterable as a parameter.
sorted_list = SortedList([1, 2, 3, 4])
  
# initializing a sorted list using default constructor
sorted_list = SortedList()
  
# inserting values one by one using add()
for i in range(5, 0, -1):
    sorted_list.add(i)
  
# prints the elements in sorted order
print('list after adding 5 elements: ', sorted_list)
  
print('list elements are: ', end = '')
  
# iterating through a sorted list
for i in sorted_list:
    print(i, end = ' ')
print()
  
# removing all elements using clear()
sorted_list.clear()
  
# adding elements using the update() function
elements = [10, 9, 8, 7, 6]
  
sorted_list.update(elements)
  
# prints the updated list in sorted order
print('list after updating: ', sorted_list)
  
# removing a particular element
sorted_list.discard(8)
  
print('list after removing one element: ', sorted_list)
  
# removing all elements
sorted_list.clear()
  
print('list after removing all elements using clear: ', sorted_list)

输出：

list after adding 5 elements:  SortedList([1, 2, 3, 4, 5], load=1000)

list elements are: 1 2 3 4 5 

list after updating:  SortedList([6, 7, 8, 9, 10], load=1000)

list after removing one element:  SortedList([6, 7, 9, 10], load=1000)

list after removing all elements using clear:  SortedList([], load=1000)

排序集 –

排序集是一个排序的可变集合，其中值是唯一的并按排序顺序维护。排序集使用集合进行集合操作并维护一个排序的值列表。排序后的集合值必须是可散列的和可比较的。

添加和删除元素的功能：

add(value) : A function that takes one element as parameter and inserts it into the set by maintaining sorted order. Runtime Complexity: O(log(n))

clear(): Remove all values from sorted set. Runtime complexity: O(n)

discard(value): Remove value from sorted set if it is a member. If value is not a member, do nothing. Runtime complexity: O(log(n))

编程需要懂一点英语

# importing libraries
from sortedcontainers import SortedList, SortedSet, SortedDict
  
# initializing a sorted set with parameters
# it takes an iterable as an argument
sorted_set = SortedSet([1, 1, 2, 3, 4])
  
# initializing a sorted set using default constructor
sorted_set = SortedSet()
  
# inserting values one by one
for i in range(5, 0, -1):
    sorted_set.add(i)
  
print('set after adding elements: ', sorted_set)
  
# inserting duplicate value
sorted_set.add(5)
  
print('set after inserting duplicate element: ', sorted_set)
  
# discarding an element
sorted_set.discard(4)
  
print('set after discarding: ', sorted_set)
  
# checking membership using 'in' operator
if(2 in sorted_set):
    print('2 is present')
else:
    print('2 is not present')
  
print('set elements are: ', end = '')
  
# iterating through a sorted set
for i in sorted_set:
    print(i, end = ' ')
print()

输出：

set after adding elements:  SortedSet([1, 2, 3, 4, 5], key=None, load=1000)

set after inserting duplicate element:  SortedSet([1, 2, 3, 4, 5], key=None, load=1000)

set after discarding:  SortedSet([1, 2, 3, 5], key=None, load=1000)

2 is present

set elements are: 1 2 3 5

排序字典 –

排序字典是排序的可变映射，其中键以排序顺序维护。 Sorted dict 继承自 dict 以存储项目并维护一个排序的键列表。排序的 dict 键必须是可散列的和可比较的。

添加和删除元素的功能：

setdefault(key, default = None) : Return value for item identified by key in sorted dict. If key is in the sorted dict then return its value. If key is not in the sorted dict then insert key with value default and return default. Runtime Complexity: O(log(n))

clear(): Remove all values from sorted dict. Runtime complexity: O(n)

get(key, default): Return the value for key if key is in the dictionary, else default.

编程需要懂一点英语

# importing libraries
from sortedcontainers import SortedList, SortedSet, SortedDict
  
# initializing a sorted dict with parameters
# it takes a dictionary object as a parameter
sorted_dict = SortedDict({'a': 1, 'b': 2, 'c': 3})
  
# initializing a sorted dict
sorted_dict = SortedDict({'a': 1, 'c': 2, 'b':3})
  
# print the dict
print('sorted dict is: ', sorted_dict)
  
# adding key => value pairs
sorted_dict['d'] = 3
  
print('sorted dict after adding an element: ', sorted_dict)
  
# adding element using setdefault()
sorted_dict.setdefault('e', 4)
  
print('sorted dict after setdefault(): ', sorted_dict)
  
# using the get function
print('using the get function to print the value of a: ', sorted_dict.get('a', 0))
  
# checking membership using 'in' operator
if('a' in sorted_dict):
    print('a is present')
else:
    print('a is not present')
  
print('dict elements are: ', end = '')
  
# iterating over key => value pairs in a dictionary
for key in sorted_dict:
    print('{} -> {}'.format(key, sorted_dict[key]), end = ' ')
print()
  
# removing all elements from the dict
sorted_dict.clear()
  
print('sorted dict after removing all elements: ', sorted_dict)

输出：

sorted dict is:  SortedDict(None, 1000, {'a': 1, 'b': 3, 'c': 2})

sorted dict after adding an element:  SortedDict(None, 1000, {'a': 1, 'b': 3, 'c': 2, 'd': 3})

sorted dict after setdefault():  SortedDict(None, 1000, {'a': 1, 'b': 3, 'c': 2, 'd': 3, 'e': 4})

using the get function to print the value of a:  1

a is present

dict elements are: a -> 1 b -> 3 c -> 2 d -> 3 e -> 4 

sorted dict after removing all elements:  SortedDict(None, 1000, {})

参考：http://www.grantjenks.com/docs/sortedcontainers/index.html