14.python中的集合

　　什么是集合？正如其字面的意思，一堆东西集中合并到一起。乍一听貌似和容器没什么差别，嗯，好吧，集合也算是一种容器。

　　在学习这个容器有什么不同之前，先看看集合是如何创建的：

a = set()   #可变集合
b = frozenset() #不可变集合
print a
print b

　　aaarticlea/png;base64,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" alt="" />

　　集合分为两种，一种是不可变的，一种是可变的，两者的差异后面会分析。

　　不过，我们创建了两个空的集合貌似么什么意思。

　　为了使其有意义，我们就先来看集合最重要的功能：去重。

a = ('aaa',123,123,123)
b = set(a)
print b

aaarticlea/png;base64,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" alt="" />

　　可以看到元祖a中的重复的元素123在集合中只剩下一个了。所以，我们总结集合的概念：

　　集合就是将不同的元素放在一起组成一个集合对象。（不影响原来的对象）

　　此时，有机智的同学看到集合里面有个方括号，立马想到了列表，并试图用索引来取值：

a = ('aaa',123,123,123)
b = set()
print b[0]

aaarticlea/png;base64,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" alt="" />

　　然而并不可以。

　　因为集合是无序的，和字典一样。

　　那么是否我们可以将集合看作是一种特殊的字典，只不过没有键，所以不能通过键去取值而已。

　　某种意义上是可以的，不过要注意，集合分为可变集合和不可变集合两种，不可变的集合就不能像字典一样修改元素。

　　另外补充一点：

a = 'abcdaabbccdd'
b = set(a)
print b

aaarticlea/png;base64,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" alt="" />

　　因为字符串也是序列，所以也可以用来去重，但是一般没什么用就是。

　　那么，对字典去重会怎么样？我们在字典中了解到了字典会自动处理键名重复的问题，那么值能进行去重吗？

a = {'a':123,'b':123}
b = set(a)
print b

aaarticlea/png;base64,iVBORw0KGgoAAAANSUhEUgAAAboAAAAqCAIAAABKhAklAAAGrklEQVR4nO2cwZXrKBBFCYsQJhEThhzBZ6fNzGSgbbN3FNqQgZPQLCQkCgooy5La3fPu+afPtxtBAcWjKEmt/gYAACBATQAAAARALgEAQATkEgAARLwnl/6h9cO/a8NoVKfU4N6th+PzLbwGN6gDxuGQtp5W1wdzNO2hlpT5DqTjfLhHHTog53nLlX54AhW5nN36rtRdmbFcprdR750Jl6i7eWH2dk22f2jV0bYim5dZSS3cy6etT8nskMLGLbNj3ORtL7twp2FhOkqDVh/Mp701V5SkzPXEfW9yrEc9rT6qtpd68SE1X0RRLr3ttX1O0zRNoylvCFGxaSk8O4F/6Ko3ePuIfrvDdaIF44awUY822OxCdZmFUt628ESEs7OwbelrL07rThw++IdW7PK4aDDpDJ571TS9Gjp9v0fxPaW9OHIMz6v5KopyGQdlkYnZHKenXaFcJvXscJ34kvRyMqY7z+PvW3geT+nsLIXzcO+k7tDwwQ3KDIaJYa8ZzH2t7Lbt1dDp2z2q6S2lMp9W83UU5VJuljPJKMQH5OWjcXMMeFdq+Fr+M//bVq+1vVL3LRJcztqzLiy5nrTMXDCLcC0tEFvoTKfUYEwX6rnCQgJzVW89TWaRMjmvOA3Z0hm53PInNCpcWg9j4pYvy1elbc3DTg+Jc22612r4x/ZK9Vp3Sg833S0jtja3GZyNalqGs4fO4FehF0tSYk3mMPMuGg3a99GozphBqbsxQ3lOR0P8MPPMUlu5b+QDkpdZM1fz7sX2NJnB5miw3nt9zakbNFb3O2p7gFxOboiyYPlK3k6Lzubrdv3Yhe7N34cAaosN8zLTxJ613SNVmdTCzjha85kWUtbAcG10FpQ4GZeXSZDLZWlLr4SZeeujUZ1izxC1tpZ6nAlSGI+YGr6m0SzrYf5ZOiuwoyqJ/Zl6Cr2o1MzPcnboJn13Zu744PzofG1UUz/kvqFt5fbkZrM+1oXwpXgm4wLkwmjUvPfimhOEq3snosP45J/VZupzEBTNDeVQvLKMays8WoobztRXDlPPeRZyY9VlO+QsGfUyMU/p7KTZtJJAJFFP0npJjLIYJ20riUBJ61/Lx/hnYmTd5mxXTuNxgaRuAYu89UI9NMrW9kHvfVdG9SVHKv0qn1DJDNIvmdwrt+U0vPfamoudqq/unchu9bRuoUan3WLcodjZdWPBP9hdnZTxtl/738rfJRbm+/MpFnJESrfIXNhFt0NrXiZFNjvslr7Fd7Op682xtF9b68yi5a6ibfnHLexkc7S11ewGdbBc5vZM5RnMaiZ59uSqyizXx7kzNnGwfFTzmiVtyaPL2McWC5mVsvU0z70WRmOqeO+VNecIV/dOJA8SNU8962k3XJIfId1Aw8BQ0ozbxmJGkl9gchlxmX//2rajO5eeYy2cC/Rah4zGiRauikAhWaT1tDVyucv6I1yt2eFu1KbZOvaBpLj1KGEUjU92FR9akqyum0I0ZwajOqX/hOze8jNK2KW5bzKqaZlCL+IZ5Hux5lKHm+6iJ886bjTi3CWthxtnZwY3PZ2L2krndLR2tMQPqWeWbObz2nTqc/8JtTGTyM8gVyatueC9l9XMb4GS1b2To97qycNmAndAvpjVwlL4+e0WHsuVz7j9+Ofp3uDAvjdPmmVaz+21+DXPWp67us9+CXLc7kx9BsstVBKNfpaF4P9J5pkS1pTfIe9i/HjOXt14ZxwAAERALgEAQATkEgAAREAuAQBABOQSAABEQC4BAEAE5BIAAEScJ5fe3qL3iY1SSimlrZ8/NR+EkpTZd1VWxls9W7d9TYwHAIDpPLl0RpO/sm7p31zXTTGSlGk3a6gKVmv21rr4k8aT6wCAiHPkMtOaSC691U0hlJQRXpXEkpWaqVzuFWwAwG/lALlMZYY7EtPo8krkh/qsH/vyAQCAX8r7csloYy4zP1IuoZcAgIiaXIb7M+EOzbTeFQmftxJxinCPXDK3W47BGWWMIZ0omgC5BACUqchlLhZr4i9O6x0SXa6XHK5QzswS3E6HQi4BADXqh3FHw7I4mKzGktlNkvZhfKv7cLkUCnEml7g5DgCIqEWXdjtyhz9cv0Zo3qfRpXObtGR6KY0uvdVFUdv9JKa2fk90CbUEAMRU5HJNJ0YBH/tEt2aCwupzlxxLIHu76VKWceeTmNa62cKW9uG5SwBAjW95q2dXbXuexBTXjbd6AAAt8M44AACIgFwCAIAIyCUAAIiAXAIAgAjIJQAAiIBcAgCACMglAACIgFwCAIAIyCUAAIj4D4dMdcb/8RhWAAAAAElFTkSuQmCC" alt="" />

　　看来还是对键的去重，并没有什么用，除非要将所以的键组合成一个集合，其去重意义不大。看业务需要吧。

　　这里，我对去重的总结是：去除重复的引用，相信看过我在python序列中的说明的人能明白这是什么意思。

　　知道去重的本质之后，我们有这个需求，我有两个容器，我想得到这两个容器去重后的结果。

　　那我这样写：

a = ('scolia',123,456,666)
b = ('scolia',666)
c = set(a,b)
print c

aaarticlea/png;base64,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" alt="" />

　　结果是大红字甩脸，说只要一个参数，结果给了两个。

　　好吧，首先看看其内部是怎么接受参数的：

aaarticlea/png;base64,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" alt="" />

　　首先，这里的__init__是构造函数，在类的创建时会讲。现在只要知道我们的参数是传给 seq=() 的，而按照这里的写法，应该是可以传一个元祖的。

　　那么是不是就可以这样写：

a = ('scolia',123,456,666)
b = ('scolia',666)
c = set((a,b))
print c

aaarticlea/png;base64,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" alt="" />

　　传是传进去了，但结果并不是我们想象的那样。

　　看来集合的去重是针对一个对象的，那么我们就可以将集合总结成：

　　集合是去除一个对象（序列或类序列的字典）中，元素的重复引用的。

　　所以我们想要实现这个需要，首先要将两个对象拼接起来:

a = ('scolia',123,456,666)
b = ('scolia',666)
c = set(a+b)
print c

aaarticlea/png;base64,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" alt="" />

　　关于序列的拼接不只一种，详情看我之前的博文。

　　而不同类型的序列先要强制转换成一种，否则报错

a = ('scolia',123,456,666)
b = ['scolia',666]
c = set(a+tuple(b))
print c

aaarticlea/png;base64,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" alt="" />

　　下面我们来开始学习其内置方法吧。

---

　　老办法，先看看帮助文档。

Help on class set in module __builtin__:

class set(object)
 |  set() -> new empty set object
 |  set(iterable) -> new set object
 |
 |  Build an unordered collection of unique elements.
 |
 |  Methods defined here:
 |
 |  __and__(...)
 |      x.__and__(y) <==> x&y
 |
 |  __cmp__(...)
 |      x.__cmp__(y) <==> cmp(x,y)
 |
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x.
 |
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 |
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 |
 |  __getattribute__(...)
 |      x.__getattribute__('name') <==> x.name
 |
 |  __gt__(...)
 |      x.__gt__(y) <==> x>y
 |
 |  __iand__(...)
 |      x.__iand__(y) <==> x&=y
 |
 |  __init__(...)
 |      x.__init__(...) initializes x; see help(type(x)) for signature
 |
 |  __ior__(...)
 |      x.__ior__(y) <==> x|=y
 |
 |  __isub__(...)
 |      x.__isub__(y) <==> x-=y
 |
 |  __iter__(...)
 |      x.__iter__() <==> iter(x)
 |
 |  __ixor__(...)
 |      x.__ixor__(y) <==> x^=y
 |
 |  __le__(...)
 |      x.__le__(y) <==> x<=y
 |
 |  __len__(...)
 |      x.__len__() <==> len(x)
 |
 |  __lt__(...)
 |      x.__lt__(y) <==> x<y
 |
 |  __ne__(...)
 |      x.__ne__(y) <==> x!=y
 |
 |  __or__(...)
 |      x.__or__(y) <==> x|y
 |
 |  __rand__(...)
 |      x.__rand__(y) <==> y&x
 |
 |  __reduce__(...)
 |      Return state information for pickling.
 |
 |  __repr__(...)
 |      x.__repr__() <==> repr(x)
 |
 |  __ror__(...)
 |      x.__ror__(y) <==> y|x
 |
 |  __rsub__(...)
 |      x.__rsub__(y) <==> y-x
 |
 |  __rxor__(...)
 |      x.__rxor__(y) <==> y^x
 |
 |  __sizeof__(...)
 |      S.__sizeof__() -> size of S in memory, in bytes
 |
 |  __sub__(...)
 |      x.__sub__(y) <==> x-y
 |
 |  __xor__(...)
 |      x.__xor__(y) <==> x^y
 |
 |  add(...)
 |      Add an element to a set.
 |
 |      This has no effect if the element is already present.
 |
 |  clear(...)
 |      Remove all elements from this set.
 |
 |  copy(...)
 |      Return a shallow copy of a set.
 |
 |  difference(...)
 |      Return the difference of two or more sets as a new set.
 |
 |      (i.e. all elements that are in this set but not the others.)
 |
 |  difference_update(...)
 |      Remove all elements of another set from this set.
 |
 |  discard(...)
 |      Remove an element from a set if it is a member.
 |
 |      If the element is not a member, do nothing.
 |
 |  intersection(...)
 |      Return the intersection of two or more sets as a new set.
 |
 |      (i.e. elements that are common to all of the sets.)
 |
 |  intersection_update(...)
 |      Update a set with the intersection of itself and another.
 |
 |  isdisjoint(...)
 |      Return True if two sets have a null intersection.
 |
 |  issubset(...)
 |      Report whether another set contains this set.
 |
 |  issuperset(...)
 |      Report whether this set contains another set.
 |
 |  pop(...)
 |      Remove and return an arbitrary set element.
 |      Raises KeyError if the set is empty.
 |
 |  remove(...)
 |      Remove an element from a set; it must be a member.
 |
 |      If the element is not a member, raise a KeyError.
 |
 |  symmetric_difference(...)
 |      Return the symmetric difference of two sets as a new set.
 |
 |      (i.e. all elements that are in exactly one of the sets.)
 |
 |  symmetric_difference_update(...)
 |      Update a set with the symmetric difference of itself and another.
 |
 |  union(...)
 |      Return the union of sets as a new set.
 |
 |      (i.e. all elements that are in either set.)
 |
 |  update(...)
 |      Update a set with the union of itself and others.
 |
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |
 |  __hash__ = None
 |
 |  __new__ = <built-in method __new__ of type object>
 |      T.__new__(S, ...) -> a new object with type S, a subtype of T

set

　　可分为以下几类：

　　1.运算符相关

　　3.内置函数相关（省略）

　　4.普通内置方法

---

1.运算符相关

　　不知道你是否还记得数学中的集合，就是那个交集、补集什么的，忘记了请自己重修。

下面用一个表格总结：

数学符号	python符号	说明
∩	&	交集，如a&b
∪	|	并集，如a|b
- 或 \	-	差补或相对补集
△	^	对称差分
⊂	<	真子集
⊆	<=	子集
⊃	>	真超集
⊇	>=	超集
=	==	等于，两个集合相等
≠	!=	不等于
∈	in	属于，是里面的元素
∉	not in	不属于

　　这部分内容只能呼叫数学老师了。我就不讲了。

---

2.普通内置方法

　　虽说在帮助文档中列出了一堆方法，但集合是分为可变的和不可变的，所以有些方法，如修改操作只有可变的集合可以使用，所以内置方法又可以分为两种：

1.所有集合都能使用的：

方法	说明
a.issubset(b)	如果a是b的子集，则返回True，否则返回False
a.issuperset(b)	如果a是b的超集，则返回True，否则返回False
a.intersection(b)	返回a和b的交集
a.union(b)	返回a和b的并集
a.difference(b)	返回一个新集合，该集合是集合a去除和b元素部分后的
a.symmetric_difference(b)	返回一个新集合，该集合是a或b的成员，但不是a和b共有的成员
a.copy()	返回一个浅拷贝。

2.可修改集合才能用的：

方法	说明
a.add()	在集合里添加新的对象
a.clear()	清空集合里的所有对象
a.pop()	删除a中的任意元素，并返回，为空时报错
a.remove(obj)	在a中删除obj这个元素，没找到时报错
a.discard(obj)	在a中删除obj这个元素，没找到时什么都不做，返回None
a.update(b)	用b中的元素修改a，此时a包含a或b的成员。相当与合并
a.intersection_update(b)	用a和b的交集更新a集合
a.difference_update(b)	从a中移除和b一样的元素
a.symmetric_difference(b)	将a修改成a和b的对称差分

---

　　这里交并补、子集超集之类的基本数学概念就不再重复了。这里讲下差补和对称差分：

1.差补

a =set( 'scolia')
b = set('good')
print a - b
print a.difference(b)

aaarticlea/png;base64,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" alt="" />

　　实际上就是干掉了 a 中的 'o'，而之所以干掉 'o' 是因为两个集合里面都有 'o'。

　　本想用数学公式来解释一番的，然而我的数学也已经遗忘到太平洋里去了。

2.对称差分

a =set( 'scolia')
b = set('good')
print a ^ b
print a.symmetric_difference(b)

　　aaarticlea/png;base64,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" alt="" />

　　将干掉两种的交集，然后把剩下来的拿出去组成新集合。

　　

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好了，集合就先讲到这里了，这么多东西我也不一定全部记得住，要用的时候再来查就行了。

参考资料：戳这里