code: def nbf(self):
      return len(self.N)
  
file_path: sympy/examples/advanced/fem.py
imports: from sympy import symbols, Symbol, factorial, Rational, zeros, eye, integrate, diff, pprint, reduced
label_desc: Use image node_id 2 for calling the Lagrange obj's underlying member method code with example usage: obj.nbf() and returns: len