Numpy automatically casting Complex to Float #551

It's been a while since i've used this awesome work you guys did.
Tried some simple things today and couldn't get it to work

I believe numpy got updated and messed some things up

Given the following code:

import control as ct
import numpy as np

# Define Poles and get it's coeficients
poles = np.array([np.complex(-7.7, 6.4), np.complex(7.7, 6.4)]) # Expecting to get these poles when G.pole() is called
coefs = np.poly(poles)

# Define the Transfer Function
num = [1]
den = coefs
G = ct.tf(num, den)

# Get the poles
G.pole()

i get these warnings:

/usr/local/lib/python3.7/dist-packages/control/xferfcn.py:957: ComplexWarning: Casting complex values to real discards the imaginary part den[j, :maxindex+1] = poly(poles[j])
/usr/local/lib/python3.7/dist-packages/control/xferfcn.py:987: ComplexWarning: Casting complex values to real discards the imaginary part num[i, j, maxindex+1-len(numpoly):maxindex+1] = numpoly array([-10.0124922, 10.0124922])

Doing a few tests i found out that

poles = np.array([np.complex(-7.7, 6.4), np.complex(7.7, 6.4)])

maxindex = 2
den = np.zeros((1, maxindex + 1), dtype=np.float)
den[0, :maxindex + 1] = np.poly(poles)

/usr/local/lib/python3.7/dist-packages/ipykernel_launcher.py:5: ComplexWarning: Casting complex values to real discards the imaginary part
will results in the same warnings, but changing dtype to np.complex it works correctly

poles = np.array([np.complex(-7.7, 6.4), np.complex(7.7, 6.4)])

maxindex = 2
den = np.zeros((1, maxindex + 1), dtype=np.complex)
den[0, :maxindex + 1] = np.poly(poles)
den

array([ 1. +0.j , 0. -12.8j, -100.25 +0.j ])

I belive changing the num and den dtype to np.complex from xferfcn.py file should solve the issue (did not look up for similar issues/solutions though)

938        den = zeros((self.inputs, maxindex + 1), dtype=np.complex)
939        num = zeros((max(1, self.outputs, self.inputs),
940                     max(1, self.outputs, self.inputs),
941                     maxindex + 1),
942                    dtype=np.complex)