Removed crypto intraday reference, added daily and exchange rate funt…

…ionality

README.md

@@ -138,10 +138,10 @@ from alpha_vantage.cryptocurrencies import CryptoCurrencies
 import matplotlib.pyplot as plt
 
 cc = CryptoCurrencies(key='YOUR_API_KEY', output_format='pandas')
-data, meta_data = cc.get_digital_currency_intraday(symbol='BTC', market='CNY')
-data['1b. price (USD)'].plot()
+data, meta_data = cc.get_digital_currency_daily(symbol='BTC', market='CNY')
+data['4b. close (USD)'].plot()
 plt.tight_layout()
-plt.title('Intraday value for bitcoin (BTC)')
+plt.title('Daily close value for bitcoin (BTC)')
 plt.grid()
 plt.show()
 ```

alpha_vantage/cryptocurrencies.py

@@ -57,3 +57,20 @@ def get_digital_currency_monthly(self, symbol, market):
         """
         _FUNCTION_KEY = 'DIGITAL_CURRENCY_MONTHLY'
         return _FUNCTION_KEY, 'Time Series (Digital Currency Monthly)', 'Meta Data'
+
+    @av._output_format
+    @av._call_api_on_func
+    def get_digital_currency_exchange_rate(self, symbol, market):
+        """ Returns the current exchange rate for a digital currency
+        (e.g., BTC) traded on a specific market (e.g., CNY/Chinese Yuan),
+        and when it was last updated.
+
+        Keyword Arguments:
+            symbol: The digital/crypto currency of your choice. It can be any
+            of the currencies in the digital currency list. For example:
+            symbol=BTC.
+            market: The exchange market of your choice. It can be any of the
+            market in the market list. For example: market=CNY.
+        """
+        _FUNCTION_KEY = 'CURRENCY_EXCHANGE_RATE'
+        return _FUNCTION_KEY, 'Dictonary (Digital Currency Exchange Rate)', 'Meta Data'