update docstring

docs/source/conf.py

@@ -34,8 +34,9 @@ release = '2019.12.21'
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-  'sphinx.ext.autodoc',
+  'sphinx.ext.autodoc',   # see also autodoc_default_options below
   'sphinx.ext.viewcode',
+  'sphinx.ext.doctest',   # see also doctest_global_setup below
 ]
 
 # Add any paths that contain templates here, relative to this directory.
@@ -92,3 +93,11 @@ html_theme_options = {
 autodoc_default_options = {
   'special-members': '__iter__, __contains__, __getitem__, __setitem__, __pos__, __neg__, __add__, __iadd__, __sub__, __isub__, __mul__, __rmul__, __imul__, __matmul__, __imatmul__, __abs__, __lt__, __le__, __gt__, __ge__, __eq__, __ne__, __str__, __repr__'
 }
+
+doctest_global_setup = '''
+from pylib.data import *
+from pylib.mathematics import *
+from pylib.function import *
+from pylib.numerical.integration import *
+from pylib.geometry2d import *
+'''