code: def get_asset_balance(self, asset, **params):
          
          res = self.get_account(**params)
          # find asset balance in list of balances
          if "balances" in res:
              for bal in res['balances']:
                  if bal['asset'].lower() == asset.lower():
                      return bal
          return None
docs: Get current asset balance.
  
          https://github.com/binance-exchange/binance-official-api-docs/blob/master/rest-api.md#account-information-user_data
  
          :param asset: required
          :type asset: str
          :param recvWindow: the number of milliseconds the request is valid for
          :type recvWindow: int
  
          :returns: dictionary or None if not found
  
          .. code-block:: python
  
              {
                  "asset": "BTC",
                  "free": "4723846.89208129",
                  "locked": "0.00000000"
              }
  
          :raises: BinanceRequestException, BinanceAPIException