code: def pg_series(k, z, n):
      """Symbolic expansion of polygamma(k, z) in z=0 to order n."""
      return sympy.diff(dg_series(z, n + k), z, k)
  
file_path: scipy/scipy/special/_precompute/wright_bessel.py
imports: from argparse import ArgumentParser, RawTextHelpFormatter
  import numpy
  from scipy.integrate import quad
  from scipy.optimize import minimize_scalar, curve_fit
  from time import time
label_desc: Use image node_id 3 for calling a global function with example usage: pg_series(k, z, n) and returns: sympy