Try Except

예외처리

• 코드를 실행중에 에러가 발생한 경우 에러를 처리하는 방법
• try, except, finally, raise

# try, except : 에러가 발생해도 코드의 실행을 계속하고 싶을때
ls = [1, 2, 3]

print(ls[3])
print("Done!")

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

IndexError                                Traceback (most recent call last)

<ipython-input-4-f88f334466aa> in <module>
----> 1 print(ls[3])
      2 print("Done!")


IndexError: list index out of range

try:
    print(ls[3])
except Exception as e:
    print("error")
    print(e)
print("Done")

error
list index out of range
Done

# finally : try, except 구문 실행된 후 finally 구문이 실행
try:
    1/0
except:
    print("error")
finally:
    print("Done!")

error
Done!

# raise : 강제로 에러를 발생시키는 명령

try:
    1/0
except Exception as e:
    print("error")
    raise(e)

print("Done!")

error



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

ZeroDivisionError                         Traceback (most recent call last)

<ipython-input-9-bcde7d6d4636> in <module>
      3 except Exception as e:
      4     print("error")
----> 5     raise(e)
      6 
      7 print("Done!")


<ipython-input-9-bcde7d6d4636> in <module>
      1 try:
----> 2     1/0
      3 except Exception as e:
      4     print("error")
      5     raise(e)


ZeroDivisionError: division by zero

# 에러 생성 : 10이상의 숫자가 입력되도록 하는 에러
# LowNumber

class LowNumber(Exception):
    
    def __str__(self):
        return "Number grater than 10"

def input_number(num):
    if num <= 10:
        raise LowNumber()
    print(num)

input_number(8)

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

LowNumber                                 Traceback (most recent call last)

<ipython-input-15-8684a0e33c0b> in <module>
----> 1 input_number(8)


<ipython-input-13-2dcc4faaa999> in input_number(num)
      1 def input_number(num):
      2     if num <= 10:
----> 3         raise LowNumber()
      4     print(num)


LowNumber: Number grater than 10