[learn Python from simple to deep] set

Set is disorder （ No index ）, Sets that do not duplicate . stay Python in , Sets are written in curly braces , Similar to the set in Mathematics .
Be careful ：

have access to Curly braces { } perhaps set() Function to create a collection , But to create an empty collection, you must use set() instead of { }, because { } Is used to create an empty dictionary ,

One 、 Define a collection

# Define a set 
s1={
1,2,3,4,5,5,6,7,7}
print(s1)

{1, 2, 3, 4, 5, 6, 7}

Two 、 Set operations

# Delete an element 
s1.remove(7)
print(s1)

{1, 2, 3, 4, 5, 6}

# To find the intersection of sets &, Combine \
s2={
1,2,4,5,6,8}
print(s1&s2)

{1, 2, 4, 5, 6}

print(s1|s2)

{1, 2, 3, 4, 5, 6, 8}

#set Method : Convert a string to a collection 
string1='Python'
s1=set(string1)
print(s1)

{‘h’, ‘P’, ‘o’, ‘y’, ‘n’, ‘t’}