Please try this…(I’m relocating/moving now and I can’t confirm it by myself, small debugging needed 
)
I think you have this code block already.
fname = "Your_Python_FileName"
run = pqs(fname)
run.qsch2cir()
Now, you open the netlist and edit.
# read the netlist, store each line in "lines" variable with the change
lines = ""
with open(run.path['cir'], encoding='SJIS') as f:
for line in f:
line = line.rstrip('\r\n')
if ret := re.match(r'^.*curr_controller_Kp', line):
new_val = 9.99
lines = lines + ".param curr_controller_Kp " + str(new_val) + "\n"
else:
lines = lines + line + "\n"
# override the netlist with "lines"
with open(run.path['cir'], "w", encoding='SJIS') as f:
f.write(lines)