use .any() instead of any() + whatsnew entry

Author: Hanspagh

doc/source/whatsnew/v1.1.3.rst

@@ -30,6 +30,7 @@ Bug fixes
 - Bug in :meth:`Series.str.startswith` and :meth:`Series.str.endswith` with ``category`` dtype not propagating ``na`` parameter (:issue:`36241`)
 - Bug in :class:`Series` constructor where integer overflow would occur for sufficiently large scalar inputs when an index was provided (:issue:`36291`)
 - Bug in :meth:`DataFrame.stack` raising a ``ValueError`` when stacking :class:`MultiIndex` columns based on position when the levels had duplicate names (:issue:`36353`)
+- Bug in :meth:`isin()` when using NaN and a row length above 1,000,000 (:issue:`22205`)
 
 .. ---------------------------------------------------------------------------
 

pandas/core/algorithms.py

@@ -442,7 +442,7 @@ def isin(comps: AnyArrayLike, values: AnyArrayLike) -> np.ndarray:
     if len(comps) > 1_000_000 and not is_object_dtype(comps):
         # If the the values include nan we need to check for nan explicitly
         # since np.nan it not equal to np.nan
-        if any(np.isnan(values)):
+        if np.isnan(values).any():
             f = lambda c, v: np.logical_or(np.in1d(c, v), np.isnan(c))
         else:
             f = np.in1d