docs: def term_code(mu, nu, coef, matrix_form, rhouv_isconjugated, linear=True):
      r"""Get code to calculate a linear term.
  
      >>> term_code(1, 0, 33, False, False, True)
      '    rhs[1] += (33)*rho[0]\n'
  
      """
      if coef == 0:
          return ""
      coef = str(coef)
  
      # We change E_{0i} -> E0[i-1]
      ini = coef.find("E_{0")
      fin = coef.find("}")
      if ini != -1:
          l = int(coef[ini+4: fin])
          coef = coef[:ini]+"Ep["+str(l-1)+"]"+coef[fin+1:]
  
      # We change r[i, j] -> r[:, i, j]
      coef = coef.replace("rp[", "rp[:, ")
      coef = coef.replace("rm[", "rm[:, ")
  
      # We change symbolic complex-operations into fast numpy functions.
      coef = coef.replace("conjugate(", "np.conjugate(")
      coef = coef.replace("re(", "np.real(")
      coef = coef.replace("im(", "np.imag(")
  
      coef = coef.replace("*I", "j")
  
      if not linear:
          if matrix_form:
              s = "    b["+str(mu)+"] += "+coef+"\n"
          else:
              s = "    rhs["+str(mu)+"] += "+coef+"\n"
          return s
  
      # We add the syntax to calculate the term and store it in memory.
      s = "    "
      if matrix_form:
          s += "A["+str(mu)+", "+str(nu)+"] += "+coef+"\n"
      else:
          s += "rhs["+str(mu)+"] += ("+coef+")"
          if rhouv_isconjugated:
              s += "*np.conjugate(rho["+str(nu)+'])\n'
          else:
              s += "*rho["+str(nu)+']\n'
  
      return s