set() and frozenset() functions generate mutable and immutable sets, respectively. : Set « Collections « Python Tutorial






print set()
print set([])
print set(())
print set('BC')
print frozenset(['foo', 'bar'])
f = open('numbers', 'w')
for i in range(5):
    f.write('%d\n' % i)
    
f.close()
f = open('numbers', 'r')
print set(f)
f.close()








9.3.Set
9.3.1.Set operations
9.3.2.How to Create and Assign Set Types
9.3.3.How to Access Values in Sets
9.3.4.How to Update Sets
9.3.5.Membership (in, not in)
9.3.6.Set Equality/Inequality
9.3.7.Subset Of/Superset Of
9.3.8.Union ( | )
9.3.9.Intersection ( & )
9.3.10.Difference/Relative Complement ( - )
9.3.11.Symmetric Difference ( ^ )
9.3.12.Mixed Set Type Operations
9.3.13.(Union) Update ( | = )
9.3.14.Retention/Intersection Update ( &= )
9.3.15.Difference Update ( - = )
9.3.16.Symmetric Difference Update ( ^ = )
9.3.17.len() returns the number of elements
9.3.18.set() and frozenset() functions generate mutable and immutable sets, respectively.