code: def _convert_string_aliases(deriv, target_shape):
      if isinstance(deriv, str):
          if deriv == "clamped":
              deriv = [(1, cupy.zeros(target_shape))]
          elif deriv == "natural":
              deriv = [(2, cupy.zeros(target_shape))]
          else:
              raise ValueError(
                  "Unknown boundary condition : %s" % deriv
              )
      return deriv
  
file_path: cupy/cupyx/scipy/interpolate/_bspline2.py
imports: import operator
  from numpy.core.multiarray import normalize_axis_index
  import cupy
  from cupyx.scipy import sparse
  from cupyx.scipy.sparse.linalg import spsolve
  from cupyx.scipy.interpolate._bspline import _get_module_func, INTERVAL_MODULE, D_BOOR_MODULE, BSpline
label_desc: Use image node_id 7 for calling a global function with example usage: _convert_string_aliases(deriv, target_shape) and returns: deriv