Run coverage checks with python3 (#4245)

Author: Chris Elion

.yamato/com.unity.ml-agents-test.yml

@@ -69,7 +69,7 @@ test_{{ package.name }}_{{ platform.name }}_{{ editor.version }}:
 
     {% if package.name == "com.unity.ml-agents" %}
     # TODO get coverage tests running for extensions too
-    - python ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
+    - python3 ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
     {% endif %}
   artifacts:
     logs:
@@ -110,7 +110,7 @@ test_{{ package.name }}_{{ platform.name }}_trunk:
     - upm-ci project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ editor.coverageOptions }}
     {% if package.name == "com.unity.ml-agents" %}
     # TODO get coverage tests running for extensions too
-    - python ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
+    - python3 ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ editor.minCoveragePct }}
     {% endif %}
   artifacts:
     logs:

ml-agents/tests/yamato/check_coverage_percent.py

@@ -3,8 +3,6 @@
 
 SUMMARY_XML_FILENAME = "Summary.xml"
 
-# Note that this is python2 compatible, since that's currently what's installed on most CI images.
-
 
 def check_coverage(root_dir, min_percentage):
     # Walk the root directory looking for the summary file that
@@ -30,16 +28,12 @@ def check_coverage(root_dir, min_percentage):
                 pct = float(pct)
                 if pct < min_percentage:
                     print(
-                        "Coverage {} is below the min percentage of {}.".format(
-                            pct, min_percentage
-                        )
+                        f"Coverage {pct} is below the min percentage of {min_percentage}."
                     )
                     sys.exit(1)
                 else:
                     print(
-                        "Coverage {} is above the min percentage of {}.".format(
-                            pct, min_percentage
-                        )
+                        f"Coverage {pct} is above the min percentage of {min_percentage}."
                     )
                     sys.exit(0)