Python错误异常怎么解决

def initiate_security_protocol(code):
    if code == 1:
        print("Returning onboard companion to home location...")
    if code == 712:
        print("Dematerializing to preset location...")

code = int(input("Enter security protocol code: "))
initiate_security_protocol(code)

>>> Enter security protocol code: 712
Dematerializing to preset location...
>>> Enter security protocol code: seven one two
Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/security_protocols.py", line 7, in <module>
    code = int(input("Enter security protocol code: "))
ValueError: invalid literal for int() with base 10: 'seven one two'

try:
    code = int(input("Enter security protocol code: "))
except ValueError:
    code = 0
initiate_security_protocol(code)

Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/security_protocols.py", line 7, in <module>
    code = int(input("Enter security protocol code: "))
ValueError: invalid literal for int() with base 10: 'seven one two'

ValueError: invalid literal for int() with base 10: '5bff'

Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/databank.py", line 6, in <module>
    decode_message("Bad Wolf")
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/databank.py", line 4, in decode_message
    initiate_security_protocol(message)
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/security_protocols.py", line 2, in initiate_security_protocol
    code = int(code)
ValueError: invalid literal for int() with base 10: 'Bad Wolf'

datafile_index = {
    # Omitted for brevity.
    # Just assume there's a lot of data in here.
}

def get_datafile_id(subject):
    id = datafile_index[subject]
    print(f"See datafile {id}.")

get_datafile_id("Clara Oswald")
get_datafile_id("Ashildir")

See datafile 6035215751266852927.

Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/databank.py", line 30, in <module>
    get_datafile_id("Ashildir")
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/databank.py", line 26, in get_datafile_id
    id = datafile_index[subject]
KeyError: 'Ashildir'

def get_datafile_id(subject):
    if subject in datafile_index:
        id = datafile_index[subject]
        print(f"See datafile {id}.")
    else:
        print(f"Datafile not found on {subject})

def get_datafile_id(subject):
    try:
        id = datafile_index[subject]
        print(f"See datafile {id}.")
    except KeyError:
        print(f"Datafile not found on {subject}")

try:
    someScaryFunction()
except:
    print("An error occured. Moving on!")

class SonicScrewdriver:

    def __init__(self):
        self.memory = 0

    def perform_division(self, lhs, rhs):
        try:
            result = float(lhs)/float(rhs)
        except ZeroDivisionError:
            print("Wibbly wobbly, timey wimey.")
            result = "Infinity"
        except (ValueError, UnicodeError):
            print("Oy! Don't diss the sonic!")
            result = "Cannot Calculate"
        else:
            self.memory = result
        finally:
            print(f"Calculation Result: {result}\n")


sonic = SonicScrewdriver()

sonic.perform_division(8, 4)
sonic.perform_division(4, 0)
sonic.perform_division(4, "zero")

print(f"Memory Is: {sonic.memory}")

Calculation Result: 2.0

Wibbly wobbly, timey wimey.
Calculation Result: Infinity

Oy! Don't diss the sonic!
Calculation Result: Cannot Calculate

Memory Is: 2.0

class SonicScrewdriver:

    def __init__(self):
        self.memory = 0

    def perform_division(self, lhs, rhs):
        try:
            result = float(lhs)/float(rhs)
        except ZeroDivisionError:
            print("Wibbly wobbly, timey wimey.")
            result = "Infinity"
        except (ValueError, UnicodeError):
            print("Oy! Don't diss the sonic!")
            result = "Cannot Calculate"
        else:
            self.memory = result
            return result
        finally:
            print(f"Calculation Result: {result}\n")
            result = -1


sonic = SonicScrewdriver()

print(sonic.perform_division(8, 4))

Calculation Result: 2.0

2.0

class Tardis:

    def __init__(self):
        pass

    def camouflage(self):
        raise NotImplementedError('Chameleon circuits are stuck.')

tardis = Tardis()
tardis.camouflage()

Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/tardis.py", line 10, in <module>
    tardis.camoflague()
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/tardis.py", line 7, in camoflague
    raise NotImplementedError('Chameleon circuits are stuck.')
NotImplementedError: Chameleon circuits are stuck.

tardis = Tardis()

try:
    tardis.camouflage()
except NotImplementedError as e:
    print(e)

Chameleon circuits are stuck.

class Byzantium:

    def __init__(self):
        self.power = 0

    def gravity_field(self):
        if self.power <= 0:
        raise SystemError("Gravity Failing")


def grab_handle():
    pass


byzantium = Byzantium()

try:
    byzantium.gravity_field()
except SystemError:
    grab_handle()
    print("Night night")
    raise

Night night
Traceback (most recent call last):
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/byzantium.py", line 18, in <module>
    byzantium.gravity_field()
  File "/home/jason/Code/FiringRanges/PyFiringRange/Sandbox/byzantium.py", line 8, in gravity_field
    raise SystemError("Gravity Failing")
SystemError: Gravity Failing

byzantium = Byzantium()

def test():
    try:
        byzantium.gravity_field()
    except SystemError:
        grab_handle()
        raise RuntimeError("Night night")

try:
    test()
except RuntimeError as e:
    print(e)
    print(e.__cause__)

Night night
None

byzantium = Byzantium()

def test():
    try:
        byzantium.gravity_field()
    except SystemError as e:
        grab_handle()
        raise RuntimeError("Night night") from e

try:
    test()
except RuntimeError as e:
    print(e)
    print(e.__cause__)

Night night
Gravity Failing

class SpacetimeError(Exception):
    def __init__(self, message):
        super().__init__(message)

class Tardis():

    def __init__(self):
        self._destination = ""
        self._timestream = []

    def cloister_bell(self):
        print("(Ominous bell tolling)")

    def dematerialize(self):
        self._timestream.append(self._destination)
        print("(Nifty whirring sound)")

    def set_destination(self, dest):
        if dest in self._timestream:
            self.cloister_bell()
        self._destination = dest

    def engage(self):
        if self._destination in self._timestream:
            raise SpacetimeError("You should not cross your own timestream!")
        else:
            self.dematerialize()


tardis = Tardis()

# Should be fine
tardis.set_destination("7775/349x10,012/acorn")
tardis.engage()

# Also fine
tardis.set_destination("5136/161x298,58/delta")
tardis.engage()

# The TARDIS is not going to like this...
tardis.set_destination("7775/349x10,012/acorn")
tardis.engage()

class SpacetimeError(Exception):
    def __init__(self, message):
        super().__init__(message)

class SpacetimeError(Exception):
    pass