35 lines
734 B
Markdown
35 lines
734 B
Markdown
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---
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title: Learn About Python Sets
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localeTitle: 了解Python集
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---
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Python中的`Set`是一种可变但无序的数据结构，它只能包含_唯一的_元素。
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**创建：**
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`set`文字：
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圆括号`{}` _不能_用于创建空集：
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```python
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>>> not_set = {} # set constructor must be used to make empty sets.
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>>> type(not_set) # Empty curly brackets create empty dictionaries.
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<class 'dict'>
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```
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您只能使用`set()`方法创建一个空集。
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```python
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>>> example_set = set()
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>>> type(example_set)
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<class 'set'>
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```
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但是，如果元素包含在大括号内，那么创建集合的语法是可以接受的。
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```python
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>>> example_set_2 = {1, 2, 3}
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>>> type(example_set_2)
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<class 'set'>
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```
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\`
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