generate Python API DOC using Sphinx

1. Install Sphinx
2. Run sphinx-quickstart to generate the doc source

   cd /path/to/my-python-project
   mkdir doc
   cd doc
   sphinx-quickstart
   

           autodoc: automatically insert docstrings from modules: Y
   

3. edit conf.py, uncomment and modify the following lines(assume python modules are in ../src/):

   import os
   import sys
   sys.path.insert(0, os.path.abspath('../src'))
   

4. Run sphinx-apidoc to generate reST files for specified modules (in ../src/):

   sphinx-apidoc -o . ../src
   

5. Generate html api doc:

   make html