Python 2.7 PyUSB请求设备状态
我正在尝试为条形码打印机编写一个脚本 这是我的密码:Python 2.7 PyUSB请求设备状态,python-2.7,libusb,pyusb,Python 2.7,Libusb,Pyusb,我正在尝试为条形码打印机编写一个脚本 这是我的密码: def printLabel(barcode, qty, articlenr=''): dev = findPrinter() dev.write("") return True if __name__ =="__main__": for i in range(2): try: # Everything works fine, the for loop breaks
def printLabel(barcode, qty, articlenr=''):
dev = findPrinter()
dev.write("")
return True
if __name__ =="__main__":
for i in range(2):
try:
# Everything works fine, the for loop breaks
printLabel('01234567890123','1', 'Hello World')
break
except usb.core.USBError as error:
if "Resource busy" in unicode(error):
# Printer is doing something, wait 3 seconds, try again
time.sleep(3)
print 'Retrying after error:"Resource busy"\n' + str(error)
printLabel('01234567890123','1', 'Hello World')
elif "Operation Timeout" in unicode(error):
# Printer is not responding
print 'ERROR! Check Paper!\n' + str(error)
else:
print 'Unknown error' + str(error)
在他尝试打印标签之前,我必须询问打印机的状态,因为如果我不能询问,他可能会进入异常中的“Resource busy”if子句,打印标签,重新开始并再次打印
但如果我能问一下他的身份,我可以说:
def waitForPrinter(dev):
dev = findPrinter()
if dev.status() is True: ## True if he is ready and False if he is Busy or something
printLabel(arguments and stuff)
else:
time.sleep(3)
waitForPrinter()
我在文档中找不到询问设备状态的函数,现在不知道如何解决这个问题
目前,我只能通过USBError获取设备状态