Merge branch 'development' into patch-1

AUTHORS

@@ -11,6 +11,7 @@ Dmytro Katyukha
 Gerard Marull-Paretas
 Hark
 Joel Lehtonen
+Justin Vieira
 kennedy
 Kristi
 ldos
@@ -20,6 +21,7 @@ Michael Billington
 Michael Elsdörfer
 mrwunderbar666
 Nathan Bookham
+Omer Akram
 Patrick Kanzler
 primax79
 Qian Linfeng

src/escpos/capabilities.py

@@ -38,7 +38,7 @@ else:
 if full_load:
     logger.debug('Loading and pickling capabilities')
     with open(capabilities_path) as cp, open(pickle_path, 'wb') as pp:
-        CAPABILITIES = yaml.load(cp)
+        CAPABILITIES = yaml.safe_load(cp)
         pickle.dump(CAPABILITIES, pp, protocol=2)
 
 logger.debug('Finished loading capabilities took %.2fs', time.time() - t0)

src/escpos/printer.py

@@ -68,6 +68,11 @@ class Usb(Escpos):
         self.idVendor = self.device.idVendor
         self.idProduct = self.device.idProduct
 
+        # pyusb has three backends: libusb0, libusb1 and openusb but
+        # only libusb1 backend implements the methods is_kernel_driver_active()
+        # and detach_kernel_driver().
+        # This helps enable this library to work on Windows.
+        if self.device.backend.__module__.endswith("libusb1"):
             check_driver = None
 
             try: