Merge pull request #666 from addisonlynch/av-order-change

BUG/TST: Adjust Alphavantage time series reader to account for descending ordering

Author: bashtage

docs/source/whatsnew/v0.8.0.txt

@@ -48,3 +48,5 @@ Bug Fixes
 
 - Fix Yahoo! actions issue where dividends are adjusted twice as a result of a
   change to the Yahoo! API. (:issue: `583`)
+- Fix AlphaVantage time series data ordering after provider switch to
+  descending order (maintains ascending order for consistency) (:issue: `662`)

pandas_datareader/av/time_series.py

@@ -80,6 +80,8 @@ def params(self):
 
     def _read_lines(self, out):
         data = super(AVTimeSeriesReader, self)._read_lines(out)
+        # reverse since alphavantage returns descending by date
+        data = data[::-1]
         start_str = self.start.strftime('%Y-%m-%d')
         end_str = self.end.strftime('%Y-%m-%d')
         data = data.loc[start_str:end_str]

pandas_datareader/tests/av/test_av_time_series.py

@@ -4,6 +4,7 @@
 import pandas as pd
 
 from pandas_datareader import data as web
+from pandas_datareader._utils import RemoteDataError
 
 from datetime import datetime
 
@@ -32,15 +33,15 @@ def end(self):
         return datetime(2017, 5, 24)
 
     def test_av_bad_symbol(self):
-        with pytest.raises(ValueError):
+        with pytest.raises((ValueError, RemoteDataError)):
             web.DataReader("BADTICKER", "av-daily", start=self.start,
                            end=self.end)
 
     def test_av_daily(self):
         df = web.DataReader("AAPL", "av-daily", start=self.start, end=self.end)
         assert df.columns.equals(self.col_index)
         assert len(df) == 578
-        assert df["volume"][-1] == 19118319
+        assert df["volume"][-1] == 19178000
 
         expected1 = df.loc["2017-02-09"]
         assert expected1["close"] == 132.42
@@ -58,19 +59,17 @@ def test_av_daily_adjusted(self):
                                            "dividend amount",
                                            "split coefficient"]))
         assert len(df) == 578
-        assert df["volume"][-1] == 19118319
+        assert df["volume"][-1] == 19178000
 
         expected1 = df.loc["2017-02-09"]
         assert expected1["close"] == 132.42
         assert expected1["high"] == 132.445
-        assert expected1["adjusted close"] == 130.3505
         assert expected1["dividend amount"] == 0.57
         assert expected1["split coefficient"] == 1.0
 
         expected2 = df.loc["2017-05-24"]
         assert expected2["close"] == 153.34
         assert expected2["high"] == 154.17
-        assert expected2["adjusted close"] == 151.5612
         assert expected2["dividend amount"] == 0.00
         assert expected2["split coefficient"] == 1.0
 
@@ -80,15 +79,10 @@ def _helper_df_weekly_monthly(df, adj=False):
         expected1 = df.loc["2015-02-27"]
         assert expected1["close"] == 128.46
         assert expected1["high"] == 133.60
-        if adj:
-            assert expected1["adjusted close"] == 121.5859
 
         expected2 = df.loc["2017-03-31"]
         assert expected2["close"] == 143.66
         assert expected2["high"] == 144.5
-        if adj:
-            assert expected2["adjusted close"] == 141.4148
-            assert expected2["dividend amount"] == 0.00
 
     def test_av_weekly(self):
         df = web.DataReader("AAPL", "av-weekly", start=self.start,