python27 tests (openai#1314)

* add py27 test environment (sans box2d and atari)

* skip mujoco tests if mujoco_py not present

* re-enable python3 tests

* remove unicode symbols

* remove more unicode symbols

gym/envs/box2d/__init__.py

@@ -1,4 +1,8 @@
-from gym.envs.box2d.lunar_lander import LunarLander
-from gym.envs.box2d.lunar_lander import LunarLanderContinuous
-from gym.envs.box2d.bipedal_walker import BipedalWalker, BipedalWalkerHardcore
-from gym.envs.box2d.car_racing import CarRacing
+try:
+    import Box2D
+    from gym.envs.box2d.lunar_lander import LunarLander
+    from gym.envs.box2d.lunar_lander import LunarLanderContinuous
+    from gym.envs.box2d.bipedal_walker import BipedalWalker, BipedalWalkerHardcore
+    from gym.envs.box2d.car_racing import CarRacing
+except ImportError:
+    Box2D = None

gym/envs/box2d/test_lunar_lander.py

@@ -1,11 +1,20 @@
-from .lunar_lander import LunarLander, LunarLanderContinuous, demo_heuristic_lander
+import pytest
+try:
+    import Box2D
+    from .lunar_lander import LunarLander, LunarLanderContinuous, demo_heuristic_lander
+except ImportError:
+    Box2D = None
 
+
+@pytest.mark.skipif(Box2D is None, reason='Box2D not installed')
 def test_lunar_lander():
     _test_lander(LunarLander(), seed=0)
 
+@pytest.mark.skipif(Box2D is None, reason='Box2D not installed')
 def test_lunar_lander_continuous():
     _test_lander(LunarLanderContinuous(), seed=0)
 
+@pytest.mark.skipif(Box2D is None, reason='Box2D not installed')
 def _test_lander(env, seed=None, render=False):
     total_reward = demo_heuristic_lander(env, seed=seed, render=render)
     assert total_reward > 100

gym/envs/classic_control/cartpole.py

@@ -23,7 +23,7 @@ class CartPoleEnv(gym.Env):
         Num	Observation                 Min         Max
         0	Cart Position             -4.8            4.8
         1	Cart Velocity             -Inf            Inf
-        2	Pole Angle                 -24°           24°
+        2	Pole Angle                 -24 deg        24 deg
         3	Pole Velocity At Tip      -Inf            Inf
         
     Actions:
@@ -38,11 +38,11 @@ class CartPoleEnv(gym.Env):
         Reward is 1 for every step taken, including the termination step
 
     Starting State:
-        All observations are assigned a uniform random value between ±0.05
+        All observations are assigned a uniform random value in [-0.05..0.05]
 
     Episode Termination:
-        Pole Angle is more than ±12°
-        Cart Position is more than ±2.4 (center of the cart reaches the edge of the display)
+        Pole Angle is more than 12 degrees
+        Cart Position is more than 2.4 (center of the cart reaches the edge of the display)
         Episode length is greater than 200
         Solved Requirements
         Considered solved when the average reward is greater than or equal to 195.0 over 100 consecutive trials.

gym/envs/tests/spec_list.py

@@ -7,8 +7,23 @@ def should_skip_env_spec_for_tests(spec):
     ep = spec._entry_point
     # Skip mujoco tests for pull request CI
     skip_mujoco = not (os.environ.get('MUJOCO_KEY'))
+    try:
+        import mujoco_py
+    except ImportError:
+        skip_mujoco = True
     if skip_mujoco and (ep.startswith('gym.envs.mujoco:') or ep.startswith('gym.envs.robotics:')):
         return True
+    try:
+        import atari_py
+    except ImportError:
+        if ep.startswith('gym.envs.atari'):
+            return True
+    try:
+        import Box2D
+    except ImportError:
+        if ep.startswith('gym.envs.box2d'):
+            return True
+
     if (    'GoEnv' in ep or
             'HexEnv' in ep or
             (ep.startswith("gym.envs.atari") and not spec.id.startswith("Pong") and not spec.id.startswith("Seaquest"))

gym/envs/tests/test_determinism.py

@@ -3,7 +3,6 @@
 
 from gym.envs.tests.spec_list import spec_list
 
-
 @pytest.mark.parametrize("spec", spec_list)
 def test_env(spec):
     # Note that this precludes running this test in multiple

tox.ini

@@ -4,16 +4,22 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py3
+envlist = py27, py3
 
 [testenv:py3]
-whitelist_externals=make
 passenv=DISPLAY MUJOCO_KEY LD_LIBRARY_PATH TRAVIS*
 deps =
     pytest
     pytest-forked
-    mock
     -e .[all]
 commands =
     pytest --forked {posargs}
 
+[testenv:py27]
+passenv=DISPLAY MUJOCO_KEY LD_LIBRARY_PATH TRAVIS*
+deps =
+    pytest
+    pytest-forked
+    -e .
+commands =
+    pytest --forked {posargs}