MAINT: Upgrade to Python 3.8

Author: bashtage

pandas_datareader/av/quotes.py

@@ -76,6 +76,6 @@ def _read_lines(self, out):
                 df["volume"] = [np.nan * len(self.symbols)]
             result.append(df)
         if len(result) != len(self.symbols):
-            raise ValueError("Not all symbols downloaded. Check valid " "ticker(s).")
+            raise ValueError("Not all symbols downloaded. Check valid ticker(s).")
         else:
             return pd.concat(result)

pandas_datareader/data.py

@@ -491,7 +491,7 @@ def DataReader(
     elif data_source == "nasdaq":
         if name != "symbols":
             raise ValueError(
-                "Only the string 'symbols' is supported for " "Nasdaq, not %r" % (name,)
+                "Only the string 'symbols' is supported for Nasdaq, not {!r}".format(name)
             )
         return get_nasdaq_symbols(retry_count=retry_count, pause=pause)
 

pandas_datareader/io/jsdmx.py

@@ -68,7 +68,7 @@ def _fix_quarter_values(value):
     if not m:
         return value
     quarter, year = m.groups()
-    value = "{}Q{}".format(quarter, year)
+    value = f"{quarter}Q{year}"
     return value
 
 

pandas_datareader/io/sdmx.py

@@ -165,10 +165,10 @@ def _get_child(element, key):
     if len(elements) == 1:
         return elements[0]
     elif len(elements) == 0:
-        raise ValueError("Element {} contains " "no {}".format(element.tag, key))
+        raise ValueError(f"Element {element.tag} contains no {key}")
     else:
         raise ValueError(
-            "Element {} contains " "multiple {}".format(element.tag, key)
+            f"Element {element.tag} contains multiple {key}"
         )
 
 

pandas_datareader/nasdaq_trader.py

@@ -42,15 +42,15 @@ def _download_nasdaq_symbols(timeout):
         ftp_session.login()
     except all_errors as err:
         raise RemoteDataError(
-            "Error connecting to {!r}: {}".format(_NASDAQ_FTP_SERVER, err)
+            f"Error connecting to {_NASDAQ_FTP_SERVER!r}: {err}"
         ) from err
 
     lines = []
     try:
         ftp_session.retrlines("RETR " + _NASDAQ_TICKER_LOC, lines.append)
     except all_errors as err:
         raise RemoteDataError(
-            "Error downloading from {!r}: {}".format(_NASDAQ_FTP_SERVER, err)
+            f"Error downloading from {_NASDAQ_FTP_SERVER!r}: {err}"
         ) from err
     finally:
         ftp_session.close()
@@ -96,12 +96,12 @@ def get_nasdaq_symbols(retry_count=3, timeout=30, pause=None):
     global _ticker_cache
 
     if timeout < 0:
-        raise ValueError("timeout must be >= 0, not {!r}".format(timeout))
+        raise ValueError(f"timeout must be >= 0, not {timeout!r}")
 
     if pause is None:
         pause = timeout / 3
     elif pause < 0:
-        raise ValueError("pause must be >= 0, not {!r}".format(pause))
+        raise ValueError(f"pause must be >= 0, not {pause!r}")
 
     if _ticker_cache is None:
         while retry_count > 0:

pandas_datareader/quandl.py

@@ -93,7 +93,7 @@ def url(self):
             "order": "asc",
             "api_key": self.api_key,
         }
-        paramstring = "&".join(["{}={}".format(k, v) for k, v in params.items()])
+        paramstring = "&".join([f"{k}={v}" for k, v in params.items()])
         url = "{url}{dataset}/{symbol}.csv?{params}"
         return url.format(
             url=self._BASE_URL, dataset=datasetname, symbol=symbol, params=paramstring

pandas_datareader/tests/test_wb.py

@@ -154,7 +154,7 @@ def test_wdi_download_error_handling(self):
         cntry_codes = ["USA"]
         inds = ["NY.GDP.PCAP.CD", "BAD_INDICATOR"]
 
-        msg = "The provided parameter value is not valid\\. " "Indicator: BAD_INDICATOR"
+        msg = "The provided parameter value is not valid\\. Indicator: BAD_INDICATOR"
         with pytest.raises(ValueError, match=msg):
             download(
                 country=cntry_codes,

pandas_datareader/tests/yahoo/test_yahoo.py

@@ -72,14 +72,14 @@ def test_get_quote_comma_name(self):
         assert df["longName"][0] == "Royal Gold, Inc."
 
     @pytest.mark.skip(
-        "Unreliable test, receive partial " "components back for dow_jones"
+        "Unreliable test, receive partial components back for dow_jones"
     )
     def test_get_components_dow_jones(self):  # pragma: no cover
         df = web.get_components_yahoo("^DJI")  # Dow Jones
         assert isinstance(df, pd.DataFrame)
         assert len(df) == 30
 
-    @pytest.mark.skip("Unreliable test, receive partial " "components back for dax")
+    @pytest.mark.skip("Unreliable test, receive partial components back for dax")
     def test_get_components_dax(self):  # pragma: no cover
         df = web.get_components_yahoo("^GDAXI")  # DAX
         assert isinstance(df, pd.DataFrame)
@@ -88,7 +88,7 @@ def test_get_components_dax(self):  # pragma: no cover
         assert df[df.name.str.contains("adidas", case=False)].index == "ADS.DE"
 
     @pytest.mark.skip(
-        "Unreliable test, receive partial " "components back for nasdaq_100"
+        "Unreliable test, receive partial components back for nasdaq_100"
     )
     def test_get_components_nasdaq_100(self):  # pragma: no cover
         # As of 7/12/13, the conditional will

pandas_datareader/wb.py

@@ -595,7 +595,7 @@ def __init__(
         freq_symbols = ["M", "Q", "A", None]
 
         if freq not in freq_symbols:
-            msg = "The frequency `{}` is not in the accepted " "list.".format(freq)
+            msg = f"The frequency `{freq}` is not in the accepted list."
             raise ValueError(msg)
 
         self.freq = freq

pandas_datareader/yahoo/options.py

@@ -62,7 +62,7 @@ class Options(_OptionBaseReader):
     >>> all_data = aapl.get_all_data()
     """
 
-    _OPTIONS_BASE_URL = "https://query1.finance.yahoo.com/" "v7/finance/options/{sym}"
+    _OPTIONS_BASE_URL = "https://query1.finance.yahoo.com/v7/finance/options/{sym}"
 
     def get_options_data(self, month=None, year=None, expiry=None):
         """
@@ -144,7 +144,7 @@ def _option_from_url(self, url):
             puts = result["options"]["puts"]
         except IndexError as exc:
             raise RemoteDataError(
-                "Option json not available " "for url: %s" % url
+                "Option json not available for url: %s" % url
             ) from exc
 
         self.underlying_price = (
@@ -479,7 +479,7 @@ def _try_parse_dates(self, year, month, expiry):
                 if expiry.year == year and expiry.month == month
             ]
             if len(expiry) == 0:
-                raise ValueError("No expiries available " "in %s-%s" % (year, month))
+                raise ValueError("No expiries available in {}-{}".format(year, month))
 
         return expiry
 
@@ -707,7 +707,7 @@ def _parse_url(self, url):
         jd = json.loads(self._read_url_as_StringIO(url).read())
         if jd is None:  # pragma: no cover
             raise RemoteDataError(
-                "Parsed URL {!r} is not " "a valid json object".format(url)
+                f"Parsed URL {url!r} is not a valid json object"
             )
         return jd