code: def nancorr(a, b, method="pearson", min_periods=None):
      """
      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
  
      f = get_corr_func(method)
      return f(a, b)
  
imports: from distutils.version import LooseVersion
  import functools
  import itertools
  import operator
  import warnings
  import numpy
  from pandas._libs import iNaT, lib, tslibs
  import pandas.compat
  from pandas.core.dtypes.cast import _int64_max, maybe_upcast_putmask
  from pandas.core.dtypes.common import _get_dtype, is_any_int_dtype, is_bool_dtype, is_complex, is_complex_dtype, is_datetime64_dtype, is_datetime64tz_dtype, is_datetime_or_timedelta_dtype, is_float, is_float_dtype, is_integer, is_integer_dtype, is_numeric_dtype, is_object_dtype, is_scalar, is_timedelta64_dtype, pandas_dtype
  from pandas.core.dtypes.dtypes import DatetimeTZDtype
  from pandas.core.dtypes.missing import isna, na_value_for_dtype, notna
  import pandas.core.common
  from pandas.core.config import get_option
label_desc: Use image node_id 29 for calling a global function with example usage: nancorr(a, b, method, min_periods) and returns: f, np