getting ready for Python 3 (#619)

* tabs to spaces
python 2 to 3: https://portingguide.readthedocs.io/en/latest/syntax.html#tabs-and-spaces

* use the new except syntax
python 2 to 3: https://portingguide.readthedocs.io/en/latest/exceptions.html#the-new-except-syntax

* make relative imports absolute
python 2 to 3: https://portingguide.readthedocs.io/en/latest/imports.html#absolute-imports

* Queue renamed to queue in python 3
Use the six compatibility library to support both python 2 and 3: https://portingguide.readthedocs.io/en/latest/stdlib-reorg.html#renamed-modules

* replace dict.has_key() with in
python 2 to 3: https://portingguide.readthedocs.io/en/latest/dicts.html#removed-dict-has-key

* make dict views compatible with python 3
python 2 to 3: https://portingguide.readthedocs.io/en/latest/dicts.html#dict-views-and-iterators
Where needed, wrapping things that will be a view in python 3 with a list(). For example, if it's accessed with []
Python 3 has no iter*() methods, so just using the values() instead of itervalues() as long as it's not too performance intensive. Note that any minor performance hit of using a list instead of a view will go away when switching to python 3. If it is intensive, we could use the six version.

* Explicitly use truncating division
python 2 to 3: https://portingguide.readthedocs.io/en/latest/numbers.html#division
python 3 treats / as float division. When we want the result to be an integer, use //

* replace map() with list comprehension where a list result is needed.
In python 3, map() returns an iterator.
python 2 to 3: https://portingguide.readthedocs.io/en/latest/iterators.html#new-behavior-of-map-and-filter

* replace filter() with list comprehension
In python 3, filter() returns an interatoooooooooooor.
python 2 to 3: https://portingguide.readthedocs.io/en/latest/iterators.html#new-behavior-of-map-and-filter

* wrap zip() in list() where we need the result to be a list
python 2 to 3: https://portingguide.readthedocs.io/en/latest/iterators.html#new-behavior-of-zip

* clean out some lint
Removes these pylint warnings:
************* Module selfdrive.car.chrysler.chryslercan
W: 15, 0: Unnecessary semicolon (unnecessary-semicolon)
W: 16, 0: Unnecessary semicolon (unnecessary-semicolon)
W: 25, 0: Unnecessary semicolon (unnecessary-semicolon)
************* Module common.dbc
W:101, 0: Anomalous backslash in string: '\?'. String constant might be missing an r prefix. (anomalous-backslash-in-string)
************* Module selfdrive.car.gm.interface
R:102, 6: Redefinition of ret.minEnableSpeed type from float to int (redefined-variable-type)
R:103, 6: Redefinition of ret.mass type from int to float (redefined-variable-type)
************* Module selfdrive.updated
R: 20, 6: Redefinition of r type from int to str (redefined-variable-type)

selfdrive/test/plant/maneuver.py

@@ -1,5 +1,5 @@
-from maneuverplots import ManeuverPlot
-from plant import Plant
+from selfdrive.test.plant.maneuverplots import ManeuverPlot
+from selfdrive.test.plant.plant import Plant
 import numpy as np
 
 

selfdrive/test/plant/plant.py

@@ -207,7 +207,7 @@ class Plant(object):
     lateral_pos_rel = 0.
 
     # print at 5hz
-    if (self.rk.frame%(self.rate/5)) == 0:
+    if (self.rk.frame % (self.rate//5)) == 0:
       print("%6.2f m  %6.2f m/s  %6.2f m/s2   %.2f ang   gas: %.2f  brake: %.2f  steer: %5.2f     lead_rel: %6.2f m  %6.2f m/s" % (distance, speed, acceleration, self.angle_steer, gas, brake, steer_torque, d_rel, v_rel))
 
     # ******** publish the car ********

selfdrive/test/plant/plant_ui.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 import pygame # pylint: disable=import-error
-from plant import Plant
+from selfdrive.test.plant.plant import Plant
 from selfdrive.car.honda.values import CruiseButtons
 import numpy as np
 import selfdrive.messaging as messaging
@@ -41,7 +41,7 @@ if __name__ == "__main__":
   plant = Plant(100, distance_lead = 40.0)
 
   control_offset = 2.0
-  control_pts = zip(np.arange(0, 100.0, 10.0), [50.0 + control_offset]*10)
+  control_pts = list(zip(np.arange(0, 100.0, 10.0), [50.0 + control_offset]*10))
 
   def pt_to_car(pt):
     x,y = pt
@@ -73,7 +73,7 @@ if __name__ == "__main__":
       x.prob = 0.0
       x.std = 1.0
 
-    car_pts = map(pt_to_car, control_pts)
+    car_pts = [pt_to_car(pt) for pt in control_pts]
 
     print(car_pts)