guarding scripts with __main__ and doc changes

tox-flakes environment tries to import the modules for
checking, and that may fail because of its dependencies

--HG--
branch : cx_freeze-support

doc/en/example/simple.txt

@@ -703,7 +703,8 @@ must declare them explicitly by using ``pytest.cx_freeze_support.includes()``::
     import pytest
 
     setup(
-        name="runtests",
+        name="app_main",
+        executables=[Executable("app_main.py")],
         options={"build_exe":
             {
             'includes': pytest.cx_freeze_support.includes()}

testing/cx_freeze/runtests_setup.py

@@ -1,14 +1,15 @@
 """
 Sample setup.py script that generates an executable with pytest runner embedded.
 """
-from cx_Freeze import setup, Executable
-import pytest
+if __name__ == '__main__':
+    from cx_Freeze import setup, Executable
+    import pytest
 
-setup(
-    name="runtests",
-    version="0.1",
-    description="exemple of how embedding py.test into an executable using cx_freeze",
-    executables=[Executable("runtests_script.py")],
-    options={"build_exe": {'includes': pytest.cx_freeze_support.includes()}},
-)
+    setup(
+        name="runtests",
+        version="0.1",
+        description="exemple of how embedding py.test into an executable using cx_freeze",
+        executables=[Executable("runtests_script.py")],
+        options={"build_exe": {'includes': pytest.cx_freeze_support.includes()}},
+    )
 

testing/cx_freeze/tox_run.py

@@ -5,10 +5,11 @@ directory.
 .. note:: somehow calling "build/runtests_script" directly from tox doesn't
           seem to work (at least on Windows).
 """
-import os
-import sys
+if __name__ == '__main__':
+    import os
+    import sys
 
-executable = os.path.join(os.getcwd(), 'build', 'runtests_script')
-if sys.platform.startswith('win'):
-    executable += '.exe'
-sys.exit(os.system('%s tests' % executable))
+    executable = os.path.join(os.getcwd(), 'build', 'runtests_script')
+    if sys.platform.startswith('win'):
+        executable += '.exe'
+    sys.exit(os.system('%s tests' % executable))