在 Python 中,可以使用单行代码以简单、直观的方式设置具有特殊条件(例如默认值或条件)的值。
result = 0 or "Does not exist." # "Does not exist."
result = "Found user!" if user in user_list else "User not found."
是否可以编写类似的捕获异常的语句?
from json import loads
result = loads('{"value": true}') or "Oh no, explosions occurred!"
# {'value': True}
result = loads(None) or "Oh no, explosions occurred!"
# "Oh no, explosions occurred!" is desired, but a TypeError is raised.
最佳答案
在 python 中不能做单行异常处理语句。可以编写一个函数来执行此操作。
def safe_execute(default, exception, function, *args):
try:
return function(*args)
except exception:
return default
示例用法:
from json import loads
safe_execute("Oh no, explosions occurred!", TypeError, loads, None)
# Returns "Oh no, explosions occurred!"
safe_execute("Huh?", TypeError, int, "10")
#Returns 10
支持多个参数
from operator import div
safe_execute(
"Divsion by zero is invalid.",
ZeroDivisionError,
div, 1, 0
)
# Returns "Divsion by zero is invalid."
safe_execute(
"Divsion by zero is invalid.",
ZeroDivisionError,
div, 1, 1
)
# Returns 1.
错误捕获过程仍有可能被中断:
from time import sleep
safe_execute(
"Panic!",
Exception,
sleep, 8
)
# Ctrl-c will raise a KeyboardInterrupt
from sys import exit
safe_execute("Failed to exit!", Exception, exit)
# Exits the Python interpreter
如果不希望出现这种行为,请使用 BaseException
:
from time import sleep
safe_execute("interrupted",
BaseException,
sleep, 8)
#Pressing Ctrl-c will return "interrupted"
from sys import exit
safe_execute("Naughty little program!",
BaseException,
exit)
#Returns "Naughty little program!"
关于python - 单行异常处理,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36671077/