Docs: update cyber/python/README.md

cyber/python/README.md

@@ -2,13 +2,12 @@
 
 ## Usage
 
-Make sure you have built Apollo successfully, which should also have added
-`/apollo/cyber/python` to the PYTHONPATH for you. Then in Python code:
+Make sure you have built Apollo successfully. Then in Python code:
 
 ```python3
 import sys
 
-from cyber_py3 import cyber
+from cyber.python.cyber_py3 import cyber
 
 
 cyber.init()
@@ -24,3 +23,6 @@ cyber.shutdown()
 Learn more usage from the [examples](cyber_py3/examples/) and
 [tests](cyber_py3/test/).
 
+**Note:** Like C++ files, Python files are also managed by Bazel since Apollo 6.0. You can take
+[how_to_build_and_run_python_app.md](../../docs/howto/how_to_build_and_run_python_app.md)
+as reference.

docs/howto/how_to_build_and_run_python_app.md

-# How to Build and Run(Test) your Python Application
+# How to Build, Test and Run your Python Application
 
-Everything managed by pure [Bazel](https://docs.bazel.build/versions/master/be/python.html) in Apollo 6.0.
+Starting from Apollo 6.0, building and testing Python applications in Apollo is
+done using [Bazel](https://docs.bazel.build/versions/master/be/python.html)
+exclusively. We use Bazel Python rules to build, run, and test Python programs.
+This not only frees us from hand-crafting Protobuf dependencies and managing
+Python related Env variables manually, but also helps with managing third party
+Python module dependency.
 
 ## Create the BUILD file
 
 Generally you need a BUILD target for each python file, which could be one of
 
-* `py_library(name="lib_target", ...)`
-* `py_binary(name="bin_target", ...)`
-* `py_test(name="test_target", ...)`
+- `py_library(name="lib_target", ...)`
+- `py_binary(name="bin_target", ...)`
+- `py_test(name="test_target", ...)`
 
 ### Example
 
@@ -48,7 +53,12 @@ py_test(
 )
 ```
 
-## Build & Run commands
+Above is a BUILD file template, you can also use the
+[BUILD](https://github.com/ApolloAuto/apollo/blob/master/cyber/python/BUILD) and
+[BUILD](https://github.com/ApolloAuto/apollo/blob/master/cyber/python/examples/BUILD)
+file as examples.
+
+## Build, Test and Run commands
 
 1. To build any target:
 
@@ -65,5 +75,5 @@ py_test(
 1. To run a unit test target:
 
    ```bash
-   bazel test //path/to:test_target
+   bazel test //path/to:target_test
    ```