examples: Add resubscribe_orderbook example

bfxapi/examples/resubscribe_orderbook.py

@@ -0,0 +1,37 @@
+import os
+import sys
+sys.path.append('../')
+
+from bfxapi import Client
+
+bfx = Client(
+  logLevel='INFO'
+)
+
+@bfx.ws.on('error')
+def log_error(err):
+  print ("Error: {}".format(err))
+
+@bfx.ws.on('unsubscribed')
+async def on_unsubscribe(subscription):
+  print ("Unsubscribed from {}".format(subscription.symbol))
+  # await subscription.subscribe()
+
+@bfx.ws.on('subscribed')
+async def on_subscribe(subscription):
+  print ("Subscribed to {}".format(subscription.symbol))
+  # await subscription.unsubscribe()
+  # or
+  # await bfx.ws.unsubscribe(subscription.chanId)
+
+@bfx.ws.once('subscribed')
+async def on_once_subscribe(subscription):
+  print ("Performig resubscribe")
+  await bfx.ws.resubscribe(subscription.chanId)
+
+
+async def start():
+  await bfx.ws.subscribe('book', 'tBTCUSD')
+
+bfx.ws.on('connected', start)
+bfx.ws.run()