42 lines
1022 B
Markdown
42 lines
1022 B
Markdown
---
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title: Learn About Python Sets
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---
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`Set`s in Python are a type of mutable but unordered data structure, which can only contain *unique* elements.
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**Creation:**
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`set` literal:
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Curly brackets, `{}`, *cannot* be used to create an empty set:
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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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You can only create an empty set by using the `set()` method.
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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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However, if elements are included within the curly brackets, then it would be acceptable syntax to create a set.
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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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### Converting List to Set
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If you want to convert a list to a set, you can do that by using the `set()` function. This will remove all duplicate values from the list.
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```python
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>>> a = [11,2,2,6,6,4,8,9,9,7]
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>>> a = set(a)
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>>> print(a) # {2, 4, 6, 7, 8, 9, 11}
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```
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