Coerce the input values array to numpy arrays with a mask

    Parameters
    ----------
    values : 1D list-like
    dtype : integer dtype
    mask : boolean 1D array, optional
    copy : boolean, default False
        if True, copy the input

    Returns
    -------
    tuple of (values, mask)

def coerce_to_array(values, dtype, mask=None, copy=False):
    """
    Coerce the input values array to numpy arrays with a mask

    Parameters
    ----------
    values : 1D list-like
    dtype : integer dtype
    mask : boolean 1D array, optional
    copy : boolean, default False
        if True, copy the input

    Returns
    -------
    tuple of (values, mask)
    """
    # if values is integer numpy array, preserve it's dtype
    if dtype is None and hasattr(values, 'dtype'):
        if is_integer_dtype(values.dtype):
            dtype = values.dtype

    if dtype is not None:
        if (isinstance(dtype, str) and
                (dtype.startswith("Int") or dtype.startswith("UInt"))):
            # Avoid DeprecationWarning from NumPy about np.dtype("Int64")
            # https://github.com/numpy/numpy/pull/7476
            dtype = dtype.lower()

        if not issubclass(type(dtype), _IntegerDtype):
            try:
                dtype = _dtypes[str(np.dtype(dtype))]
            except KeyError:
                raise ValueError("invalid dtype specified {}".format(dtype))

    if isinstance(values, IntegerArray):
        values, mask = values._data, values._mask
        if dtype is not None:
            values = values.astype(dtype.numpy_dtype, copy=False)

        if copy:
            values = values.copy()
            mask = mask.copy()
        return values, mask

    values = np.array(values, copy=copy)
    if is_object_dtype(values):
        inferred_type = lib.infer_dtype(values, skipna=True)
        if inferred_type == 'empty':
            values = np.empty(len(values))
            values.fill(np.nan)
        elif inferred_type not in ['floating', 'integer',
                                   'mixed-integer', 'mixed-integer-float']:
            raise TypeError("{} cannot be converted to an IntegerDtype".format(
                values.dtype))

    elif not (is_integer_dtype(values) or is_float_dtype(values)):
        raise TypeError("{} cannot be converted to an IntegerDtype".format(
            values.dtype))

    if mask is None:
        mask = isna(values)
    else:
        assert len(mask) == len(values)

    if not values.ndim == 1:
        raise TypeError("values must be a 1D list-like")
    if not mask.ndim == 1:
        raise TypeError("mask must be a 1D list-like")

    # infer dtype if needed
    if dtype is None:
        dtype = np.dtype('int64')
    else:
        dtype = dtype.type

    # if we are float, let's make sure that we can
    # safely cast

    # we copy as need to coerce here
    if mask.any():
        values = values.copy()
        values[mask] = 1
        values = safe_cast(values, dtype, copy=False)
    else:
        values = safe_cast(values, dtype, copy=False)

    return values, mask