Multiple Try-Excepts followed by an Else in python

Question

Is there some way to have several consecutive Try-Except clauses that trigger a single Else only if all of them are successful?

As an example:

 try:
    private.anodization_voltage_meter = Voltmeter(voltage_meter_address.value) #assign voltmeter location
except(visa.VisaIOError): #channel time out
    private.logger.warning('Volt Meter is not on or not on this channel')
try:
    private.anodization_current_meter = Voltmeter(current_meter_address.value) #assign voltmeter as current meter location
except(visa.VisaIOError): #channel time out
    private.logger.warning('Ammeter is not on or not on this channel')
try:
    private.sample_thermometer = Voltmeter(sample_thermometer_address.value)#assign voltmeter as thermomter location for sample.
except(visa.VisaIOError): #channel time out
    private.logger.warning('Sample Thermometer is not on or not on this channel')
try:
    private.heater_thermometer = Voltmeter(heater_thermometer_address.value)#assign voltmeter as thermomter location for heater.
except(visa.VisaIOError): #channel time out
    private.logger.warning('Heater Thermometer is not on or not on this channel')
else:
    private.logger.info('Meters initialized')

As you can see, you only want to print meters initialized if all of them went off, however as currently written it only depends on the heater thermometer. is there some way to stack these?

Answer 1

Personally I'd just have a trip variable init_ok or somesuch.

Set it as True, and have all the except clauses set it False, then test at the end?

Answer 2

Consider breaking the try/except structure into a function that returns True if the call worked and False if it failed, then use e.g. all() to see that they all succeded:

def initfunc(structure, attrname, address, desc):
  try:
    var = Voltmeter(address.value)
    setattr(structure, attrname, var)
    return True
  except(visa.VisaIOError):
    structure.logger.warning('%s is not on or not on this channel' % (desc,))

if all([initfunc(*x) for x in [(private, 'anodization_voltage_meter', voltage_meter_address, 'Volt Meter'), ...]]):
  private.logger.info('Meters initialized')