Improve style in drive_helpers (#23962)

selfdrive/controls/lib/drive_helpers.py

@@ -54,7 +54,7 @@ def update_v_cruise(v_cruise_kph, buttonEvents, button_timers, enabled, metric):
   long_press = False
   button_type = None
 
-  v_cruise_delta = 1 if metric else 1.6
+  v_cruise_delta = 1. if metric else CV.MPH_TO_KPH
 
   for b in buttonEvents:
     if b.type.raw in button_timers and not b.pressed:
@@ -91,9 +91,9 @@ def initialize_v_cruise(v_ego, buttonEvents, v_cruise_last):
 
 def get_lag_adjusted_curvature(CP, v_ego, psis, curvatures, curvature_rates):
   if len(psis) != CONTROL_N:
-    psis = [0.0 for i in range(CONTROL_N)]
-    curvatures = [0.0 for i in range(CONTROL_N)]
-    curvature_rates = [0.0 for i in range(CONTROL_N)]
+    psis = [0.0]*CONTROL_N
+    curvatures = [0.0]*CONTROL_N
+    curvature_rates = [0.0]*CONTROL_N
 
   # TODO this needs more thought, use .2s extra for now to estimate other delays
   delay = CP.steerActuatorDelay + .2