[test][execution] Move conda related helper out of class

That will make them re-usable in other tests like
in beat/beat.cmdline>

beat/core/test/test_execution.py

@@ -58,6 +58,39 @@ from .utils import slow
 
 logger = logging.getLogger(__name__)
 
+
+# ----------------------------------------------------------
+# Helpers
+
+
+def create_conda_environment(additional_packages=[]):
+    environment_name = "subprocess_environment"
+    environment_prefix = os.path.join(tmp_prefix, environment_name)
+    packages = ["python=3"] + additional_packages
+    sp.run(
+        [
+            "conda",
+            "create",
+            "-y",
+            "-c",
+            "defaults",
+            "-c",
+            "http://www.idiap.ch/software/bob/conda/",
+            "--prefix",
+            environment_prefix,
+        ]
+        + packages,
+        check=True,
+        stdout=sp.PIPE,
+        stderr=sp.PIPE,
+    )
+    return environment_prefix
+
+
+def clear_conda_environment(environment_prefix):
+    rmtree(environment_prefix)
+
+
 # ----------------------------------------------------------
 
 
@@ -463,35 +496,9 @@ class TestSubprocessExecution(BaseExecutionMixIn):
             result["user_error"], "'Could not setup algorithm (returned False)'"
         )
 
-    def create_conda_environment(self, additional_packages=[]):
-        environment_name = "subprocess_environment"
-        environment_prefix = os.path.join(tmp_prefix, environment_name)
-        packages = ["python=3"] + additional_packages
-        sp.run(
-            [
-                "conda",
-                "create",
-                "-y",
-                "-c",
-                "defaults",
-                "-c",
-                "http://www.idiap.ch/software/bob/conda/",
-                "--prefix",
-                environment_prefix,
-            ]
-            + packages,
-            check=True,
-            stdout=sp.PIPE,
-            stderr=sp.PIPE,
-        )
-        return environment_prefix
-
-    def clear_conda_environment(self, environment_prefix):
-        rmtree(environment_prefix)
-
     @slow
     def test_different_environment(self):
-        environment_prefix = self.create_conda_environment(["beat.backend.python"])
+        environment_prefix = create_conda_environment(["beat.backend.python"])
         result = self.execute(
             "user/user/loop/1/loop",
             [{"sum": 135, "nb": 9}, {"sum": 9, "nb": 9}],
@@ -499,13 +506,13 @@ class TestSubprocessExecution(BaseExecutionMixIn):
                 "python_path": os.path.join(environment_prefix, "bin", "python")
             },
         )
-        self.clear_conda_environment(environment_prefix)
+        clear_conda_environment(environment_prefix)
 
         nose.tools.assert_is_none(result)
 
     @slow
     def test_wrong_different_environment(self):
-        environment_prefix = self.create_conda_environment()
+        environment_prefix = create_conda_environment()
         with nose.tools.assert_raises(RuntimeError):
             self.execute(
                 "user/user/loop/1/loop",
@@ -514,4 +521,4 @@ class TestSubprocessExecution(BaseExecutionMixIn):
                     "python_path": os.path.join(environment_prefix, "bin", "python")
                 },
             )
-        self.clear_conda_environment(environment_prefix)
+        clear_conda_environment(environment_prefix)