code: def _get_forward_norm(n, norm):
      if n < 1:
          raise ValueError(
              f"Invalid number of FFT data points ({n}) specified."
          )
  
      if norm is None or norm == "backward":
          return 1
      elif norm == "ortho":
          return sqrt(n)
      elif norm == "forward":
          return n
      raise ValueError(
          f'Invalid norm value {norm}; should be "backward",'
          '"ortho" or "forward".'
      )
  
imports: import functools
  from numpy.core import asarray, zeros, swapaxes, conjugate, take, sqrt
  from .None import _pocketfft_internal
  from numpy.core.multiarray import normalize_axis_index
  from numpy.core import overrides
label_desc: Use image node_id 2 for calling a global function with example usage: _get_forward_norm(n, norm) and returns: int, sqrt, n