Add /examples/websocket/auth/calc.py demo to show how calc works.

examples/websocket/auth/calc.py

@@ -0,0 +1,40 @@
+# python -c "import examples.websocket.auth.calc"
+
+import os
+
+from bfxapi import Client
+from bfxapi.types import BaseMarginInfo, FundingInfo, SymbolMarginInfo
+
+bfx = Client(
+    api_key=os.getenv("BFX_API_KEY"),
+    api_secret=os.getenv("BFX_API_SECRET"),
+)
+
+
+@bfx.wss.on("authenticated")
+async def on_authenticated(_):
+    await bfx.wss.inputs.calc("margin_base")
+
+    await bfx.wss.inputs.calc("margin_sym_tBTCUSD")
+
+    await bfx.wss.inputs.calc("funding_sym_fUST")
+
+
+@bfx.wss.on("base_margin_info")
+def on_base_margin_info(data: BaseMarginInfo):
+    print("Base margin info:", data)
+
+
+@bfx.wss.on("symbol_margin_info")
+def on_symbol_margin_info(data: SymbolMarginInfo):
+    if data.symbol == "tBTCUSD":
+        print("Symbol margin info:", data)
+
+
+@bfx.wss.on("funding_info_update")
+def on_funding_info_update(data: FundingInfo):
+    if data.symbol == "fUST":
+        print("Funding info update:", data)
+
+
+bfx.wss.run()