Python continues after CTRL-C

[kjbolhuis]

I have a programm running continious controlling the heatpump, fan and air-inlet to control the climate. This programm runs for more than a year now, but twice there the programm stopped running without an error. After a CTRL-C it proceeds. I found the code stopped in the included part of te code.

def read_weergegevens(_orig_sens_buiten, _orig_sens_max_buiten, _orig_sens_min_buiten, _orig_sens_rv_buiten,_orig_sens_i_buiten ):
    try:
       _var_response = requests.get("https://www.weerstationtzandt.nl/realtime.txt")
       _var_weer = csv.reader(_var_response.text.strip().split('\n'),delimiter =' ')
       for _var_weergegevens in _var_weer:
          _sens_buiten = float(_var_weergegevens[2])
          _sens_max_buiten = float(_var_weergegevens[26])
          _sens_min_buiten = float(_var_weergegevens[28])
          _sens_rv_buiten = float(_var_weergegevens[3])
          _sens_press_buiten = float(_var_weergegevens[10]) 
          _sens_i_buiten = _calc_enthalpy(_sens_buiten,_sens_rv_buiten,_sens_press_buiten/10)
          return _sens_buiten, _sens_max_buiten, _sens_min_buiten, _sens_rv_buiten , _sens_i_buiten
    except:
       return _orig_sens_buiten, _orig_sens_max_buiten, _orig_sens_min_buiten, _orig_sens_rv_buiten , _orig_sens_i_buiten

This piece of programm reads a frequently updated online file from nearby weatherstation and collects data from it.

What can cause this behaviour and how can i prevent it.