[Python] Generator

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Generator

• list와 같은 iterable객체와 달리 대용량의 memory를 사용하지 않음
  • 그러나 반대로 여러번 값을 가져올 수 없음
• next함수를 통해 다음 generator의 값을 가져올 수 있음
• 함수 안의 yield를 통해 generator을 만들 수도 있음

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lannister = ['cersei', 'jaime', 'tywin', 'tyrion', 'joffrey']
lengths = (len(person) for person in lannister)

for value in lengths:
    print(value)

6
5
5
6
7

lannister = ['cersei', 'jaime', 'tywin', 'tyrion', 'joffrey']
lengths = (len(person) for person in lannister)

print(next(lengths))
print(next(lengths))
print(next(lengths))
print(next(lengths))
print(next(lengths))
print(next(lengths)) # 더이상 없으므로 StopIteration 에러 발생

6
5
5
6
7



---------------------------------------------------------------------------

StopIteration                             Traceback (most recent call last)

/var/folders/6k/3q6ftyyn3v1gswgzvq0rxsf80000gn/T/ipykernel_31849/842899953.py in <module>
      7 print(next(lengths))
      8 print(next(lengths))
----> 9 print(next(lengths)) # 더이상 없으므로 StopIteration 에러 발생


StopIteration: 

def get_lengths(input_list):
    for person in input_list:
        yield len(person)
        
lannister = ['cersei', 'jaime', 'tywin', 'tyrion', 'joffrey']
for value in get_lengths(lannister):
    print(value)

6
5
5
6
7

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