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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _putmask_smart(v, m, n):
 """ Return a new ndarray, try to preserve dtype if possible. Parameters v : `values`, updated in-place (array like) m : `mask`, applies to both sides (array like) n : `new values` either scalar or an array like aligned with `values` Returns ------- values : ndarray with updated values this *may* be a copy of the original See Also -------- ndarray.putmask """


    # we cannot use np.asarray() here as we cannot have conversions
    # that numpy does when numeric are mixed with strings

    # n should be the length of the mask or a scalar here
    if not is_list_like(n):
        n = np.repeat(n, len(m))
    elif isinstance(n, np.ndarray) and n.ndim == 0:  # numpy scalar
        n = np.repeat(np.array(n, ndmin=1), len(m))

    # see if we are only masking values that if putted
    # will work in the current dtype
    try:
        nn = n[m]

        # make sure that we have a nullable type
        # if we have nulls
        if not _isna_compat(v, nn[0]):
            raise ValueError

        # we ignore ComplexWarning here
        with warnings.catch_warnings(record=True):
            warnings.simplefilter("ignore", np.ComplexWarning)
            nn_at = nn.astype(v.dtype)

        # avoid invalid dtype comparisons
        # between numbers & strings

        # only compare integers/floats
        # don't compare integers to datetimelikes
        if (not is_numeric_v_string_like(nn, nn_at) and
            (is_float_dtype(nn.dtype) or
             is_integer_dtype(nn.dtype) and
             is_float_dtype(nn_at.dtype) or
             is_integer_dtype(nn_at.dtype))):

            comp = (nn == nn_at)
            if is_list_like(comp) and comp.all():
                nv = v.copy()
                nv[m] = nn_at
                return nv
    except (ValueError, IndexError, TypeError, OverflowError):
        pass

    n = np.asarray(n)

    def _putmask_preserve(nv, n):
        try:
            nv[m] = n[m]
        except (IndexError, ValueError):
            nv[m] = n
        return nv

    # preserves dtype if possible
    if v.dtype.kind == n.dtype.kind:
        return _putmask_preserve(v, n)

    # change the dtype if needed
    dtype, _ = maybe_promote(n.dtype)

    if is_extension_type(v.dtype) and is_object_dtype(dtype):
        v = v.get_values(dtype)
    else:
        v = v.astype(dtype)

    return _putmask_preserve(v, n)