Add optional retry mechanism for transient network errors

Author: axisrow

doc/source/advanced/config.rst

@@ -13,3 +13,15 @@ Set proxy once in config, affects all yfinance data fetches.
 
    import yfinance as yf
    yf.set_config(proxy="PROXY_SERVER")
+
+Retries
+-------
+
+Configure automatic retry for transient network errors. The retry mechanism uses exponential backoff (1s, 2s, 4s...).
+
+.. code-block:: python
+
+   import yfinance as yf
+   yf.set_config(retries=2)
+
+Set to 0 to disable retries (default behavior).

tests/test_prices.py

@@ -2,6 +2,7 @@
 from tests.context import session_gbl
 
 import unittest
+import socket
 
 import datetime as _dt
 import pytz as _tz
@@ -456,6 +457,21 @@ def test_aggregate_capital_gains(self):
 
         dat.history(start=start, end=end, interval=interval)
 
+    def test_transient_error_detection(self):
+        """Test that _is_transient_error correctly identifies transient vs permanent errors"""
+        from yfinance.data import _is_transient_error
+        from yfinance.exceptions import YFPricesMissingError
+
+        # Transient errors (should retry)
+        self.assertTrue(_is_transient_error(socket.error("Network error")))
+        self.assertTrue(_is_transient_error(TimeoutError("Timeout")))
+        self.assertTrue(_is_transient_error(OSError("OS error")))
+
+        # Permanent errors (should NOT retry)
+        self.assertFalse(_is_transient_error(ValueError("Invalid")))
+        self.assertFalse(_is_transient_error(YFPricesMissingError('INVALID', '')))
+        self.assertFalse(_is_transient_error(KeyError("key")))
+
 
 if __name__ == '__main__':
     unittest.main()

yfinance/__init__.py

@@ -49,9 +49,11 @@
 
 # Config stuff:
 _NOTSET=object()
-def set_config(proxy=_NOTSET, hide_exceptions=_NOTSET):
+def set_config(proxy=_NOTSET, retries=_NOTSET, hide_exceptions=_NOTSET):
     if proxy is not _NOTSET:
         YfData(proxy=proxy)
+    if retries is not _NOTSET:
+        YfConfig(retries=retries)
     if hide_exceptions is not _NOTSET:
         YfConfig(hide_exceptions=hide_exceptions)
 __all__ += ["set_config"]

yfinance/config.py

@@ -17,17 +17,28 @@ def __call__(cls, *args, **kwargs):
                 if 'hide_exceptions' in kwargs or (args and len(args) > 0):
                     hide_exceptions = kwargs.get('hide_exceptions') if 'hide_exceptions' in kwargs else args[0]
                     cls._instances[cls]._set_hide_exceptions(hide_exceptions)
+                if 'retries' in kwargs or (args and len(args) > 1):
+                    retries = kwargs.get('retries') if 'retries' in kwargs else args[1]
+                    cls._instances[cls]._set_retries(retries)
             return cls._instances[cls]
 
 
 class YfConfig(metaclass=SingletonMeta):
-    def __init__(self, hide_exceptions=True):
+    def __init__(self, hide_exceptions=True, retries=0):
         self._hide_exceptions = hide_exceptions
+        self._retries = retries
 
     def _set_hide_exceptions(self, hide_exceptions):
         self._hide_exceptions = hide_exceptions
 
+    def _set_retries(self, retries):
+        self._retries = retries
+
     @property
     def hide_exceptions(self):
         return self._hide_exceptions
+
+    @property
+    def retries(self):
+        return self._retries
 

yfinance/data.py

@@ -1,5 +1,7 @@
 import functools
 from functools import lru_cache
+import socket
+import time as _time
 
 from curl_cffi import requests
 from urllib.parse import urlsplit, urljoin
@@ -9,10 +11,23 @@
 from frozendict import frozendict
 
 from . import utils, cache
+from .config import YfConfig
 import threading
 
 from .exceptions import YFException, YFDataException, YFRateLimitError
 
+
+def _is_transient_error(exception):
+    """Check if error is transient (network/timeout) and should be retried."""
+    if isinstance(exception, (TimeoutError, socket.error, OSError)):
+        return True
+    error_type_name = type(exception).__name__
+    transient_error_types = {
+        'Timeout', 'TimeoutError', 'ConnectionError', 'ConnectTimeout',
+        'ReadTimeout', 'ChunkedEncodingError', 'RemoteDisconnected',
+    }
+    return error_type_name in transient_error_types
+
 cache_maxsize = 64
 
 
@@ -416,7 +431,15 @@ def _make_request(self, url, request_method, body=None, params=None, timeout=30)
         if body:
             request_args['json'] = body
 
-        response = request_method(**request_args)
+        for attempt in range(YfConfig().retries + 1):
+            try:
+                response = request_method(**request_args)
+                break
+            except Exception as e:
+                if _is_transient_error(e) and attempt < YfConfig().retries:
+                    _time.sleep(2 ** attempt)
+                else:
+                    raise
         utils.get_yf_logger().debug(f'response code={response.status_code}')
         if response.status_code >= 400:
             # Retry with other cookie strategy

yfinance/multi.py

@@ -286,12 +286,10 @@ def _download_one(ticker, start=None, end=None,
                 rounding=rounding, keepna=keepna, timeout=timeout,
                 raise_errors=True
         )
+        shared._DFS[ticker.upper()] = data
     except Exception as e:
-        # glob try/except needed as current thead implementation breaks if exception is raised.
         shared._DFS[ticker.upper()] = utils.empty_df()
         shared._ERRORS[ticker.upper()] = repr(e)
         shared._TRACEBACKS[ticker.upper()] = traceback.format_exc()
-    else:
-        shared._DFS[ticker.upper()] = data
 
     return data