數據類型之set

數據類型之集合 set

set集合，是一個無序且不重覆的元素集合

A = set([1, 2, 3, 4, 5, 6,])
B = set([2, 3, 4, 5, 6, 7, 8])
type(A)
<class 'set'>
type(B)
<class 'set'>

class set(object):
"""
set() -> new empty set object
set(iterable) -> new set object
 
Build an unordered collection of unique elements.
"""
def add(self, *args, **kwargs): # real signature unknown
    """
    Add an element to a set，添加元素
     
    This has no effect if the element is already present.
    """
    pass

def clear(self, *args, **kwargs): # real signature unknown
    """ Remove all elements from this set. 清除內容"""
    pass

def copy(self, *args, **kwargs): # real signature unknown
    """ Return a shallow copy of a set. 淺拷貝  """
    pass

def difference(self, *args, **kwargs): # real signature unknown
    """
    Return the difference of two or more sets as a new set. A中存在，B中不存在
     
    (i.e. all elements that are in this set but not the others.)
    """
    pass
//  >>> A = set([1, 2, 3, 4, 5, 6,])
    >>> B = set([2, 3, 4, 5, 6, 7, 8])
    >>> 
    >>> 
    >>> A.difference(B)
    {1}

def difference_update(self, *args, **kwargs): # real signature unknown
    """ Remove all elements of another set from this set.  從當前集合中刪除和B中相同的元素"""
    pass
//  >>> A.difference_update(B)
>>> A
{1}
>>> B
{2, 3, 4, 5, 6, 7, 8}

def discard(self, *args, **kwargs): # real signature unknown
    """
    Remove an element from a set if it is a member.
     
    If the element is not a member, do nothing. 移除指定元素，不存在不保留
    """
    pass
//  >>> A
{1, 2, 3, 4, 5, 6}

>>> A.discard(4)
>>> A
{1, 2, 3, 5, 6}

def intersection(self, *args, **kwargs): # real signature unknown
    """
    Return the intersection of two sets as a new set. 交集
     
    (i.e. all elements that are in both sets.)
    """
    pass
//  >>> A
    {1, 2, 3, 5, 6}
    >>> B
    {2, 3, 4, 5, 6, 7, 8}
    >>> A.intersection(B)
    {2, 3, 5, 6}

def intersection_update(self, *args, **kwargs): # real signature unknown
    """ Update a set with the intersection of itself and another.  取交集並更更新到A中 """
    pass
//  >>> A
    {1, 2, 3, 5, 6}
    >>> B
    {2, 3, 4, 5, 6, 7, 8}
    >>> A.intersection_update(B)
    >>> A
    {2, 3, 5, 6}

def isdisjoint(self, *args, **kwargs): # real signature unknown
    """ Return True if two sets have a null intersection.  如果沒有交集，返回True，否則返回False"""
    pass

def issubset(self, *args, **kwargs): # real signature unknown
    """ Report whether another set contains this set.  是否是子序列"""
    pass

def issuperset(self, *args, **kwargs): # real signature unknown
    """ Report whether this set contains another set. 是否是父序列"""
    pass

def pop(self, *args, **kwargs): # real signature unknown
    """
    Remove and return an arbitrary set element.
    Raises KeyError if the set is empty. 移除元素
    """
    pass

def remove(self, *args, **kwargs): # real signature unknown
    """
    Remove an element from a set; it must be a member.
     
    If the element is not a member, raise a KeyError. 移除指定元素，不存在保錯
    """
    pass

def symmetric_difference(self, *args, **kwargs): # real signature unknown
    """
    Return the symmetric difference of two sets as a new set.  對稱差集
     
    (i.e. all elements that are in exactly one of the sets.)
    """
    pass
//  >>> A
    {2, 3, 5, 6}
    >>> B
    {2, 3, 4, 5, 6, 7, 8}
    >>> A.symmetric_difference(B)  //取出兩者異同數據
    {4, 7, 8}

def symmetric_difference_update(self, *args, **kwargs): # real signature unknown
    """ Update a set with the symmetric difference of itself and another. 對稱差集，並更新到a中 """
    pass
//  >>> A
    {2, 3, 5, 6}
    >>> B
    {2, 3, 4, 5, 6, 7, 8}
    >>> A.symmetric_difference_update(B)
    >>> A
    {4, 7, 8}
 
def union(self, *args, **kwargs): # real signature unknown
    """
    Return the union of sets as a new set.  並集
     
    (i.e. all elements that are in either set.)
    """
    pass
//  >>> A
    {4, 7, 8}
    >>> B
    {2, 3, 4, 5, 6, 7, 8}
    >>> A.union(B)
    {2, 3, 4, 5, 6, 7, 8}

def update(self, *args, **kwargs): # real signature unknown
    """ Update a set with the union of itself and others. 更新 """
    pass
//  >>> A
    {4, 7, 8}
    >>> B
{2, 3, 4, 5, 6, 7, 8}
>>> A.update(B)
>>> A
{2, 3, 4, 5, 6, 7, 8}

• 練習

  # 資料庫中原有
  old_dict = {
      "#1":{ 'hostname':'c1', 'cpu_count': 2, 'mem_capicity': 80 },
      "#2":{ 'hostname':'c1', 'cpu_count': 2, 'mem_capicity': 80 },
      "#3":{ 'hostname':'c1', 'cpu_count': 2, 'mem_capicity': 80 }
  }
  
  # cmdb 新彙報的數據
  new_dict = {
      "#1":{ 'hostname':'c1', 'cpu_count': 2, 'mem_capicity': 800 },
      "#3":{ 'hostname':'c1', 'cpu_count': 2, 'mem_capicity': 80 },
      "#4":{ 'hostname':'c2', 'cpu_count': 2, 'mem_capicity': 80 }
  }
  #需求三張表:
  #需要刪除：？
  #需要新建：？
  #需要更新：？
  #註意：無需考慮內部元素是否改變，只要原來存在，新彙報也存在，就是需要更新
  
  scripts:
  
  #!/usr/bin/env python
  old = set(old_dict.keys())
  new = set(new_dict.keys())
  
  update_set = old.intersection(new)   # 交集
  
  delete_set = old.symmetric_difference(update_set)   #對稱差集
  
  add_set = new.symmetric_difference(update_set)
  
  print(update_set)
  print(delete_set)
  print(add_set)