1. 수학적 set 연산자
- Union
- A | B
- Intersection
- A & B
- Difference
- A - B
- Symmetric Difference
- A ^ B
👎
popular_users = ['a', 'b']
active_users = ['b', 'c']
popular_and_active_users = []
for user in active_users:
if user in popular_users:
popular_and_active_users.append(user)
print(popular_and_active_users)
['b']
👍
print(set(['a', 'b']) & set(['b', 'c']))
{'b'}
2. set comprehension을 사용해서 간결하게 표현
👎
users_first_names = set()
users = [{'first_name': 'yein', 'last_name': 'lee'}, {'first_name': 'gildong', 'last_name': 'hong'}]
for user in users:
users_first_names.add(user.get('first_name'))
print(users_first_names)
{'yein', 'gildong'}
👍
users_first_names = set()
users = [{'first_name': 'yein', 'last_name': 'lee'}, {'first_name': 'gildong', 'last_name': 'hong'}]
users_first_names = {user.get('first_name') for user in users}
print(users_first_names)
{'gildong', 'yein'}
3. 중복 없애기
👎
l = []
for user in ['a', 'b', 'b']:
if user not in l:
l.append(user)
print(l)
['a', 'b']
👍
l = (set(['a', 'b', 'b']))
print(l)
{'b', 'a'}