The built-in function set() is used to create sets in python. The set is a single variable that stores multiple data it should be unordered and unindexed, and cannot allow duplicate values.
set(iterable) #where iterable can be string,tuple,set,dictionary,etc
It takes a single parameter.Using { } we cannot create empty sets it creates an empty dictionary so we use set() to create an empty set.
| Parameter | Description | Required / Optional |
|---|---|---|
| iterable | a sequence (string, tuple, etc.) or collection (set, dictionary, etc.) or an iterator object to be converted into a set | Optional |
We cannot modify sets after their creation.
| Input | Return Value |
|---|---|
| no parameters | an empty set |
| iterable parameter | a set constructed from the given iterable |
# empty set
print(set())
# from string
print(set('Python'))
# from tuple
print(set(('a', 'e', 'i', 'o', 'u')))
# from list
print(set(['a', 'e', 'i', 'o', 'u']))
# from range
print(set(range(5)))
Output:
set()
{'P', 'o', 't', 'n', 'y', 'h'}
{'a', 'o', 'e', 'u', 'i'}
{'a', 'o', 'e', 'u', 'i'}
{0, 1, 2, 3, 4}
# from set
print(set({'a', 'e', 'i', 'o', 'u'}))
# from dictionary
print(set({'a':1, 'e': 2, 'i':3, 'o':4, 'u':5}))
# from frozen set
frozen_set = frozenset(('a', 'e', 'i', 'o', 'u'))
print(set(frozen_set))
Output:
{'a', 'o', 'i', 'e', 'u'}
{'a', 'o', 'i', 'e', 'u'}
{'a', 'o', 'e', 'u', 'i'}
class PrintNumberlist:
def __init__(self, max):
self.max = max
def __iter__(self):
self.num = 0
return self
def __next__(self):
if(self.num >= self.max):
raise StopIteration
self.num += 1
return self.num
# print_num is an iterable
print_number = PrintNumberlist(5)
# creating a set
print(set(print_number))
Output:
{1, 2, 3, 4, 5}
