From a8a22fcfcb7311f5f1be61c4e7c9dd99d639c758 Mon Sep 17 00:00:00 2001
From: Joris Van den Bossche <jorisvandenbossche@gmail.com>
Date: Wed, 23 Dec 2020 23:37:04 +0100
Subject: [PATCH] Backport PR #38657: DOC/CI: fix class alias docstrings for
 sphinx 3.4 + unpin sphinx

---
 doc/source/conf.py   | 25 +++++++++++++++++++++++++
 environment.yml      |  2 +-
 requirements-dev.txt |  2 +-
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/doc/source/conf.py b/doc/source/conf.py
index 15e7a13ff5b72..951a6d4043786 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -687,6 +687,30 @@ def process_class_docstrings(app, what, name, obj, options, lines):
         lines[:] = joined.split("\n")
 
 
+_BUSINED_ALIASES = [
+    "pandas.tseries.offsets." + name
+    for name in [
+        "BDay",
+        "CDay",
+        "BMonthEnd",
+        "BMonthBegin",
+        "CBMonthEnd",
+        "CBMonthBegin",
+    ]
+]
+
+
+def process_business_alias_docstrings(app, what, name, obj, options, lines):
+    """
+    Starting with sphinx 3.4, the "autodoc-process-docstring" event also
+    gets called for alias classes. This results in numpydoc adding the
+    methods/attributes to the docstring, which we don't want (+ this
+    causes warnings with sphinx).
+    """
+    if name in _BUSINED_ALIASES:
+        lines[:] = []
+
+
 suppress_warnings = [
     # We "overwrite" autosummary with our PandasAutosummary, but
     # still want the regular autosummary setup to run. So we just
@@ -716,6 +740,7 @@ def setup(app):
     app.connect("source-read", rstjinja)
     app.connect("autodoc-process-docstring", remove_flags_docstring)
     app.connect("autodoc-process-docstring", process_class_docstrings)
+    app.connect("autodoc-process-docstring", process_business_alias_docstrings)
     app.add_autodocumenter(AccessorDocumenter)
     app.add_autodocumenter(AccessorAttributeDocumenter)
     app.add_autodocumenter(AccessorMethodDocumenter)
diff --git a/environment.yml b/environment.yml
index 1ac190830c132..b99b856187fb6 100644
--- a/environment.yml
+++ b/environment.yml
@@ -31,7 +31,7 @@ dependencies:
   # documentation
   - gitpython  # obtain contributors from git for whatsnew
   - gitdb
-  - sphinx=3.3.1
+  - sphinx
 
   # documentation (jupyter notebooks)
   - nbconvert>=5.4.1
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 137c0db5f4408..17ca6b8401501 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -17,7 +17,7 @@ pycodestyle
 pyupgrade
 gitpython
 gitdb
-sphinx==3.3.1
+sphinx
 nbconvert>=5.4.1
 nbsphinx
 pandoc