python第七天set集合

Posted 2020-12-02 breaki

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集合（set）：可变数据类型（不可哈希）,它里面的元素必须是不可变数据类型，无序，不重复
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# set1 = {1, 2, 3}
# print(set1)  # {1, 2, 3}

set1 = {"Break", "前端", "19", "男"}

# 增加
set1.add("LOL")
print(set1)  # {‘Break‘, ‘前端‘, ‘LOL‘, ‘男‘, ‘19‘}

# update
set1.update("abc")
print(set1)  # {‘a‘, ‘男‘, ‘b‘, ‘Break‘, ‘19‘, ‘前端‘, ‘c‘, ‘LOL‘}

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# 刪除 随机删除
set1.pop()  # 删除并返回被删除的元素
print(set1)  # {‘19‘, ‘Break‘, ‘c‘, ‘a‘, ‘b‘, ‘男‘, ‘前端‘}
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# remove 删除指定元素
set1.remove("b")  # 没有钙元素会报错
print(set1)  # {‘b‘, ‘LOL‘, ‘男‘, ‘c‘, ‘前端‘, ‘19‘}

# clear 清空集合
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set1.clear()
print(set) # <class ‘set‘>
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# del 删除集合
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del set1
print(set1) # NameError: name ‘set1‘ is not defined
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# 查 查询只能用for
# for i in set1:
#     print(i)
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前端
19
a
LOL
男
c
Break
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#  求交集 & 或者 intersection  查询两个都有的元素
set1 = {1, 2, 3, 4, 5}
set2 = {4, 5, 6, 7, 8}
print(set1 & set2)  # {4, 5}
print(set1.intersection(set2))  # {4, 5}
# 求并集 | 或者 union
print(set1 | set2)  # {1, 2, 3, 4, 5, 6, 7, 8}
print(set1.union(set2))  # {1, 2, 3, 4, 5, 6, 7, 8}

# 求反交集
print(set1 ^ set2)  # {1, 2, 3, 6, 7, 8}
print(set1.symmetric_difference(set2))  # {1, 2, 3, 6, 7, 8}

# 求差集 set1独有的
print(set1 - set2)  # {1, 2, 3}
print(set1.difference(set2))  # {1, 2, 3}

# 子集 set2 是否包含set1
print(set1 < set2)  # False
print(set1.issubset(set2))  # False

# 超集
print(set1 > set2)  # False


# 去除重复的元素
li = [1, 2, 2, 4, 5, 88, 77, 99, 88]
set3 = set(li)
li = list(set3)
print(li)