python整理-Day3

Posted 2020-07-14

set

无须，不重复,可嵌套的集合

  1 class set(object): 
  2     """ 
  3     set() -> new empty set object 
  4     set(iterable) -> new set object 
  5       
  6     Build an unordered collection of unique elements. 
  7     """
  8     def add(self, *args, **kwargs): # real signature unknown 
  9         """ 
 10         Add an element to a set，添加元素 
 11           
 12         This has no effect if the element is already present. 
 13         """
 14         pass
 15   
 16     def clear(self, *args, **kwargs): # real signature unknown 
 17         """ Remove all elements from this set. 清除内容"""
 18         pass
 19   
 20     def copy(self, *args, **kwargs): # real signature unknown 
 21         """ Return a shallow copy of a set. 浅拷贝  """
 22         pass
 23   
 24     def difference(self, *args, **kwargs): # real signature unknown 
 25         """ 
 26         Return the difference of two or more sets as a new set. A中存在，B中不存在 
 27           
 28         (i.e. all elements that are in this set but not the others.) 
 29         """
 30         pass
 31   
 32     def difference_update(self, *args, **kwargs): # real signature unknown 
 33         """ Remove all elements of another set from this set.  从当前集合中删除和B中相同的元素"""
 34         pass
 35   
 36     def discard(self, *args, **kwargs): # real signature unknown 
 37         """ 
 38         Remove an element from a set if it is a member. 
 39           
 40         If the element is not a member, do nothing. 移除指定元素，不存在不保错 
 41         """
 42         pass
 43   
 44     def intersection(self, *args, **kwargs): # real signature unknown 
 45         """ 
 46         Return the intersection of two sets as a new set. 交集 
 47           
 48         (i.e. all elements that are in both sets.) 
 49         """
 50         pass
 51   
 52     def intersection_update(self, *args, **kwargs): # real signature unknown 
 53         """ Update a set with the intersection of itself and another.  取交集并更更新到A中 """
 54         pass
 55   
 56     def isdisjoint(self, *args, **kwargs): # real signature unknown 
 57         """ Return True if two sets have a null intersection.  如果没有交集，返回True，否则返回False"""
 58         pass
 59   
 60     def issubset(self, *args, **kwargs): # real signature unknown 
 61         """ Report whether another set contains this set.  是否是子序列"""
 62         pass
 63   
 64     def issuperset(self, *args, **kwargs): # real signature unknown 
 65         """ Report whether this set contains another set. 是否是父序列"""
 66         pass
 67   
 68     def pop(self, *args, **kwargs): # real signature unknown 
 69         """ 
 70         Remove and return an arbitrary set element. 
 71         Raises KeyError if the set is empty. 移除元素 
 72         """
 73         pass
 74   
 75     def remove(self, *args, **kwargs): # real signature unknown 
 76         """ 
 77         Remove an element from a set; it must be a member. 
 78           
 79         If the element is not a member, raise a KeyError. 移除指定元素，不存在保错 
 80         """
 81         pass
 82   
 83     def symmetric_difference(self, *args, **kwargs): # real signature unknown 
 84         """ 
 85         Return the symmetric difference of two sets as a new set.  对称差集 
 86           
 87         (i.e. all elements that are in exactly one of the sets.) 
 88         """
 89         pass
 90   
 91     def symmetric_difference_update(self, *args, **kwargs): # real signature unknown 
 92         """ Update a set with the symmetric difference of itself and another. 对称差集，并更新到a中 """
 93         pass
 94   
 95     def union(self, *args, **kwargs): # real signature unknown 
 96         """ 
 97         Return the union of sets as a new set.  并集 
 98           
 99         (i.e. all elements that are in either set.) 
100         """
101         pass
102   
103     def update(self, *args, **kwargs): # real signature unknown 
104         """ Update a set with the union of itself and others. 更新 """
105         pass 

练习：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author:wzc

dic1={
    "a":"8",
    "b":"4",
    "d":"2",
}

dic2={
    "a":"4",
    "b":"4",
    "c":"2",
}

old_dic=set(dic1)
print(old_dic)
new_dic=set(dic2)
print(new_dic)
add_key=old_dic.difference(new_dic)
print(add_key)
del_key=new_dic.difference(old_dic)
print(del_key)
up_key=list(old_dic.intersection(new_dic))
print(up_key)
for i in list(up_key):
    #print(dic1[i],dic2[i])
    if dic1[i] != dic2[i]:
        print(i)

 展示结果：

{‘a‘, ‘d‘, ‘b‘}
{‘a‘, ‘c‘, ‘b‘}
{‘d‘}
{‘c‘}
[‘a‘, ‘b‘]
a

 

函数

定义和使用

函数的定义主要有如下要点：

• def：表示函数的关键字
• 函数名：函数的名称，日后根据函数名调用函数
• 函数体：函数中进行一系列的逻辑计算，如：发送邮件、计算出 [11,22,38,888,2]中的最大数等...
• 参数：为函数体提供数据
• 返回值：当函数执行完毕后，可以给调用者返回数据。