Correctly generate API docs with Sphinx on readthedocs

See readthedocs/readthedocs.org#5512

Author: JiaweiZhuang

doc/conf.py

@@ -43,6 +43,10 @@
 # NOT to sort autodoc functions in alphabetical order
 autodoc_member_order = 'bysource'
 
+# To avoid installing xESMF and all its dependencies when building doc
+# https://stackoverflow.com/a/15912502/8729698
+autodoc_mock_imports = ['numpy', 'xarray', 'scipy', 'ESMF']
+
 # avoid automatic execution for notebooks
 nbsphinx_execute = 'never'
 

doc/requirements.txt

@@ -1,3 +1,4 @@
 numpydoc
 ipython
 nbsphinx
+git+https://github.com/JiaweiZhuang/xESMF

setup.py

@@ -1,4 +1,5 @@
 from setuptools import setup, find_packages
+import os
 
 VERSION = '0.1.1'
 DISTNAME = 'xesmf'
@@ -8,7 +9,14 @@
 URL = 'https://github.com/JiaweiZhuang/xESMF'
 LICENSE = 'MIT'
 PYTHON_REQUIRES = '>=3.5'
-INSTALL_REQUIRES = ['esmpy', 'xarray', 'numpy', 'scipy']
+
+# https://github.com/rtfd/readthedocs.org/issues/5512#issuecomment-475024373
+on_rtd = os.environ.get('READTHEDOCS') == 'True'
+if on_rtd:
+    INSTALL_REQUIRES = []
+else:
+    INSTALL_REQUIRES = ['esmpy', 'xarray', 'numpy', 'scipy']
+
 CLASSIFIERS = [
     'Development Status :: 4 - Beta',
     'License :: OSI Approved :: MIT License',