code: def _norm(x):
      return np.sqrt(np.sum(x * x))
  
imports: import numpy
  import pandas
  from statsmodels.tools.sm_exceptions import ValueWarning, EstimationWarning
  from statsmodels.tools.validation import string_like, array_like, bool_like, float_like, int_like
label_desc: Use image node_id 1 for calling a global function with example usage: _norm(x) and returns: np