1、常见异常的产生
1）除0运算——ZeroDivisionError
2）找不到可读文件——FileNotFoundError
3）值错误——ValueError
4）索引错误——IndexError
5）类型错误——TypeError
6）变量名错误——NameError
2、异常的处理
1）try_except
① 单分支
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| x = 10
y = 0
try:
z = x/y
except ZeroDivisionError:
print("0不能作除数")
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② 多分支
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| ls = []
d = {"name":"LC"}
try:
d["age"]
except NameError:
print("变量名不存在")
except IndexError:
print("索引超出界限")
except KeyError:
print("键不存在")
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③ 万能异常 Exception
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| ls = []
d = {"name":"LC"}
try:
d["age"]
except Exception:
print("出错了")
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④ 捕获异常的值 as
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| ls = []
d = {"name":"LC"}
try:
y = m
d["age"]
except Exception as e:
print(e)
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2）try_except_else
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| try:
with open("try.txt") as f:
text = f.read()
except FileNotFoundError:
print("找不到文件")
else:
print("找到了")
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3）try_except_finally：无论try模块是否执行，finally最后都会执行
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| ls = []
d = {"name":"LC"}
try:
y = x
ls[3]
d["age"]
except Exception as e:
print(e)
finally:
print("执行finally")
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