code: def nancorr(
      a: np.ndarray,
      b: np.ndarray,
      *,
      method: CorrelationMethod = "pearson",
      min_periods: int | None = None,
  ) -> float:
      """
      a, b: ndarrays
      """
      if len(a) != len(b):
          raise AssertionError(
              "Operands to nancorr must have same size"
          )
  
      if min_periods is None:
          min_periods = 1
  
      valid = notna(a) & notna(b)
      if not valid.all():
          a = a[valid]
          b = b[valid]
  
      if len(a) < min_periods:
          return np.nan
  
      a = _ensure_numeric(a)
      b = _ensure_numeric(b)
  
      f = get_corr_func(method)
      return f(a, b)
  
imports: from __future__ import annotations
  import functools
  import itertools
  from typing import Any, Callable, cast
  import warnings
  import numpy
  from pandas._config import get_option
  from pandas._libs import NaT, NaTType, iNaT, lib
  from pandas._typing import ArrayLike, AxisInt, CorrelationMethod, Dtype, DtypeObj, F, Scalar, Shape, npt
  from pandas.compat._optional import import_optional_dependency
  from pandas.util._exceptions import find_stack_level
  from pandas.core.dtypes.common import is_complex, is_float, is_float_dtype, is_integer, is_numeric_dtype, is_object_dtype, needs_i8_conversion, pandas_dtype
  from pandas.core.dtypes.missing import isna, na_value_for_dtype, notna
label_desc: Use image node_id 35 for calling a global function with example usage: nancorr(a, b) and returns: f, np