# set #

python  set , , set  dict  set  value 


## 1set  ##

 set list 

```python
set1=set([123,456,789])
print(set1)
```



```
{456, 123, 789}
```

 `[123,456,789]`  list `{456, 123, 789}`  set  456, 123, 789  3  list  set 

tuple () list () , dict () dict  dict  key-value  set  key 

 dict   key  key-value   set 


```python
set1=set([123,456,789,123,123])
print(set1)
```



```
{456, 123, 789}
```

## 2set  ##

 add(key)  set 

```python
set1=set([123,456,789])
print(set1)
set1.add(100)
print(set1)
set1.add(100)
print(set1)
```


```
{456, 123, 789}
{456, 123, 100, 789}
{456, 123, 100, 789}
```

## 3set  ##

 remove(key)  set 

```python
set1=set([123,456,789])
print(set1)
set1.remove(456)
print(set1)
```



```
{456, 123, 789}
{123, 789}
```


## 4set  ##

 set  set  union(), intersection(), difference() 

![set](http://upload-images.jianshu.io/upload_images/2136918-733b1d1071f772bd?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)



```python
set1=set('hello')
set2=set(['p','y','y','h','o','n'])
print(set1)
print(set2)

#  ( set )
set3=set1 & set2
print('\n set3:')
print(set3)
#   set 
set4=set1 | set2
print('\n set4:')
print(set4)
# 
set5=set1 - set2
set6=set2 - set1
print('\n set5:')
print(set5)
print('\n set6:')
print( set6)


#  hash  set 
list1 = [111,222,333,444,111,222,333,444,555,666]  
set7=set(list1)
print('\n set7:')
print(set7)

```



```
{'h', 'l', 'e', 'o'}
{'h', 'n', 'o', 'y', 'p'}

 set3:
{'h', 'o'}

 set4:
{'h', 'p', 'n', 'e', 'o', 'y', 'l'}

 set5:
{'l', 'e'}

 set6:
{'p', 'y', 'n'}

 set7:
{555, 333, 111, 666, 444, 222}
```