Backport ticker tz verification for nice error

ranaroussi · Oct 31, 2022 · 23b6ad1 · 23b6ad1
1 parent e99e61f
commit 23b6ad1
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Showing 2 changed files with 42 additions and 29 deletions.
diff --git a/yfinance/base.py b/yfinance/base.py
@@ -150,17 +150,14 @@ def history(self, period="1mo", interval="1d",
 
         if start or period is None or period.lower() == "max":
             # Check can get TZ. Fail => probably delisted
-            try:
-                tz = self._get_ticker_tz(debug_mode, proxy, timeout)
-            except KeyError as e:
-                if "exchangeTimezoneName" in str(e):
-                    shared._DFS[self.ticker] = utils.empty_df()
-                    shared._ERRORS[self.ticker] = err_msg
-                    if "many" not in kwargs and debug_mode:
-                        print('- %s: %s' % (self.ticker, err_msg))
-                    return utils.empty_df()
-                else:
-                    raise
+            tz = self._get_ticker_tz(debug_mode, proxy, timeout)
+            if tz is None:
+                # Every valid ticker has a timezone. Missing = problem
+                shared._DFS[self.ticker] = utils.empty_df()
+                shared._ERRORS[self.ticker] = err_msg
+                if "many" not in kwargs and debug_mode:
+                    print('- %s: %s' % (self.ticker, err_msg))
+                return utils.empty_df()
 
             if end is None:
                 end = int(_time.time())
@@ -336,6 +333,19 @@ def _get_ticker_tz(self, debug_mode, proxy, timeout):
             return self._tz
 
         tkr_tz = utils.cache_lookup_tkr_tz(self.ticker)
+
+        if tkr_tz is not None:
+            invalid_value = isinstance(tkr_tz, str)
+            if not invalid_value:
+                try:
+                    _tz.timezone(tz)
+                except:
+                    invalid_value = True
+            if invalid_value:
+                # Clear from cache and force re-fetch
+                utils.cache_store_tkr_tz(self.ticker, None)
+                tkr_tz = None
+
         if tkr_tz is None:
             tkr_tz = self._fetch_ticker_tz(debug_mode, proxy, timeout)
 

diff --git a/yfinance/utils.py b/yfinance/utils.py
@@ -336,32 +336,35 @@ def cache_lookup_tkr_tz(tkr):
         return None
 
     mutex.acquire()
-    df = _pd.read_csv(fp)
+    df = _pd.read_csv(fp, index_col="Ticker")
     mutex.release()
-    f = df["Ticker"] == tkr
-    if sum(f) == 0:
+    if tkr in df.index:
+        return df.loc[tkr,"Tz"]
+    else:
         return None
-
-    return df["Tz"][f].iloc[0]
 def cache_store_tkr_tz(tkr,tz):
-    df = _pd.DataFrame({"Ticker":[tkr], "Tz":[tz]})
 
     dp = get_cache_dirpath()
+    fp = _os.path.join(dp, "tkr-tz.csv")
     mutex.acquire()
     if not _os.path.isdir(dp):
         _os.makedirs(dp)
-    fp = _os.path.join(dp, "tkr-tz.csv")
-    if not _os.path.isfile(fp):
-        df.to_csv(fp, index=False)
-        mutex.release()
-        return
-
-    df_all = _pd.read_csv(fp)
-    f = df_all["Ticker"]==tkr
-    if sum(f) > 0:
-        mutex.release()
-        raise Exception("Tkr {} tz already in cache".format(tkr))
+    if (not _os.path.isfile(fp)) and (tz is not None):
+        df = _pd.DataFrame({"Tz":[tz]}, index=[tkr])
+        df.index.name = "Ticker"
+        df.to_csv(fp)
 
-    _pd.concat([df_all,df]).to_csv(fp, index=False)
+    else:
+        df = _pd.read_csv(fp, index_col="Ticker")
+        if tz is None:
+            # Delete if in cache:
+            if tkr in df.index:
+                df.drop(tkr).to_csv(fp)
+        else:
+            if tkr in df.index:
+                raise Exception("Tkr {} tz already in cache".format(tkr))
+            df.loc[tkr,"Tz"] = tz
+            df.to_csv(fp)
+
     mutex.release()