[PY2.7.11] 예외 처리(Exception)

/************************************************************************************************

-- Title : [PY2.7.11] 예외 처리(Exception)

-- Reference : itsdong.com

-- Key word : 예외처리 예외 처리 try except else finally

************************************************************************************************/

-- utf-8

# -*- coding: utf-8 -*-
 
#-- 에러의 예
#    FileNotFoundError : 파일이 없을 때
#    ZeroDivisionError : 숫자를 0으로 나룰 때
#    IndexError : 구문 오류
#    EOF : 파일의 끝(읽을 내용이 없을 때)
 
# --------------------------------------------
# -- try~except 추가
# --------------------------------------------
# -- TEST.py 저장
try:
    str = input('Input some string >> ')
    print(str)
except EOFError:
    print ('There is no string.')
 
 
# -- 실행(정상)
D:\Python> python TEST.py
Input some string >> 'hahaha'
hahaha
 
# -- 실행(exception)
D:\Python> python TEST.py
Input some string >> ^Z
There is no string.
 
# --------------------------------------------
# -- Exception 추가 및 else 처리
# --------------------------------------------
 
try:
    str = input('Input some string >> ')
    print(str)
 
except EOFError:
    print ('There is no string.')       #  ^Z 눌러보소.
except KeyboardInterrupt:
    print ('Canceled input string.')    # ^C 눌러보소.
else:
    print ('String you input is {}.'.format(str))
# -- 실행
D:\Python> python TEST.py
Input some string >> ^C
Cnaceled input string.
 
D:\Python> python TEST.py
Input some string >> 'ggg'
String you input is ggg.
 
# --------------------------------------------
# -- try~finally 추가
#    에러가 발생해도 finally문을 항상 수행
# --------------------------------------------
 
try:
    str = input('Input some string >> ')
except EOFError:
    print ('There is no string.')       #  ^Z 눌러보소.
except KeyboardInterrupt:
    print ('Canceled input string.')    # ^C 눌러보소.
else:
    print ('String you input is {}.'.format(str))
finally:
    print ('It has executed command.')
# -- 실행(exception)
D:\Python> python TEST.py
Input some string >> ^Z
It has executed command.
 
# --------------------------------------------
# -- try~except~pass 추가
#    특정 에러가 발생해도 그냥 통과
# --------------------------------------------
try:
    fp = open('nofile.txt', 'r')
except FileNotFoundError                # 3.0 이상에서만 되나??? 에러남.
    pass
 
# --------------------------------------------
# -- raise 추가
#    에러를 강제로 발생시키는 방법
# --------------------------------------------
 
class Flight:
    def fly(self):
        raise NotImplementedError  # 내장 에러로 구현되지 않을 때 방생
 
class Plane(Flight)
    pass
 
plane = Plane()
plane.fly()
# --------------------------------------------
# -- 사용자 예외 발생 시키기
# --------------------------------------------
class UserException(Exception):
    def __init__(self, length, minimum):
        self.length = length
        self.minimum = minimum
 
try:
    txt = input("Input string >> ")
    if len(txt) < 5:
        raise UserException(len(txt), 5)
 
except EOFError:                            # ^Z 눌러보소
    print("No string!!")
 
except KeyboardInterrupt:                   # ^C 눌러보소
    print("Cancled input string!!")
 
except UserException as uex:
    print("UserException: Input string size is {0}. Size bigger than min. {1}".format(uex.length, uex.minimum))
 
else:
    print("There is no excetion!!")
 
'''
C:\python27\python.exe C:/python27/Project/20160425/test.py
Input string >> "aaaaaa"
There is no excetion!!

C:\python27\python.exe C:/python27/Project/20160425/test.py
Input string >> "aaa"
UserException: Input string size is 3. Size bigger than min. 5
'''
 
 
 

-- cp949

# -*- coding: cp949 -*-
 
import sys
import time
 
fp = None
 
try:
    fp = open("text.txt", "r")
 
    while True:
        line = fp.readline()
        if len(line) == 0:
            break
        print(line)
 
        sys.stdout.flush()    # 화면에 바로바로 출력하라.
        time.sleep(2)         # S단위로 자라.
 
except EOFError:              # ^Z 눌러보소
    print("There is no file to read!!")
 
except KeyboardInterrupt:     # 출력 중간에  ㅊㅌㅋ4+^C 눌러보소
    print("User canceled!!")
 
finally:                      # 예외 처리 후에도 실행되는 finally
    if fp:
        fp.close()
    print("File has been closed!!")
 
'''
C:\python27\python.exe C:/python27/Project/20160425/test2.py
하나하면 할머니가 지팡이 들고서 덜덜덜

두울하면 두부장수 두부를 판다고 덜덜덜
File has been closed!!
'''