update documentation to explicitly import kwant.continuum

doc/source/code/figure/discretize.py.diff

-@@ -1,222 +1,236 @@
+@@ -1,225 +1,239 @@
  # Tutorial 2.9. Processing continuum Hamiltonians with discretize
  # ===============================================================
  #
@@ -13,6 +13,9 @@
 +import _defs
  
  import kwant
+ #HIDDEN_BEGIN_import
+ import kwant.continuum
+ #HIDDEN_END_import
  import scipy.sparse.linalg
  import scipy.linalg
  import numpy as np

doc/source/code/figure/plot_qahe.py.diff

-@@ -1,71 +1,75 @@
+@@ -1,72 +1,76 @@
  # Comprehensive example: quantum anomalous Hall effect
  # ====================================================
  #
@@ -16,6 +16,7 @@
  import math
  import matplotlib.pyplot
  import kwant
+ import kwant.continuum
  
  
  # 2 band model exhibiting quantum anomalous Hall effect

doc/source/conf.py

@@ -16,7 +16,9 @@ import sys, os
 from distutils.util import get_platform
 sys.path.insert(0, "../../build/lib.{0}-{1}.{2}".format(
         get_platform(), *sys.version_info[:2]))
+
 import kwant
+import kwant.continuum  # sphinx gets confused with lazy loading
 
 # -- General configuration -----------------------------------------------------
 

doc/source/tutorial/discretize.rst

@@ -53,6 +53,11 @@ with :math:`A(x) = \frac{\hbar^2}{2 m(x)}`.
 
 Using `~kwant.continuum.discretize` to obtain a template
 ........................................................
+First we must explicitly import the `kwant.continuum` package:
+
+.. literalinclude:: /code/include/discretize.py
+    :start-after: #HIDDEN_BEGIN_import
+    :end-before: #HIDDEN_END_import
 
 The function `kwant.continuum.discretize` takes a symbolic Hamiltonian and
 turns it into a `~kwant.builder.Builder` instance with appropriate spatial