Merge remote-tracking branch 'upstream/master' into docstrings_dataframe_describe

* upstream/master: (158 commits)
  Add link to "Craft Minimal Bug Report" blogpost (pandas-dev#20431)
  BUG: fixed json_normalize for subrecords with NoneTypes (pandas-dev#20030) (pandas-dev#20399)
  BUG: ExtensionArray.fillna for scalar values (pandas-dev#20412)
  DOC" update the Pandas core window rolling count docstring" (pandas-dev#20264)
  DOC: update the pandas.DataFrame.plot.hist docstring (pandas-dev#20155)
  DOC: Only use ~ in class links to hide prefixes. (pandas-dev#20402)
  Bug: Allow np.timedelta64 objects to index TimedeltaIndex (pandas-dev#20408)
  DOC: add disallowing of Series construction of len-1 list with index to whatsnew (pandas-dev#20392)
  MAINT: Remove weird pd file
  DOC: update the Index.isin docstring (pandas-dev#20249)
  BUG: Handle all-NA blocks in concat (pandas-dev#20382)
  DOC: update the pandas.core.resample.Resampler.fillna docstring (pandas-dev#20379)
  BUG: Don't raise exceptions splitting a blank string (pandas-dev#20067)
  DOC: update the pandas.DataFrame.cummax docstring (pandas-dev#20336)
  DOC: update the pandas.core.window.x.mean docstring (pandas-dev#20265)
  DOC: update the api.types.is_number docstring (pandas-dev#20196)
  Fix linter (pandas-dev#20389)
  DOC: Improved the docstring of pandas.Series.dt.to_pytimedelta (pandas-dev#20142)
  DOC: update the pandas.Series.dt.is_month_end docstring (pandas-dev#20181)
  DOC: update the window.Rolling.min docstring (pandas-dev#20263)
  ...

Author: nehiljain

.gitignore

@@ -61,6 +61,7 @@ dist
 .coverage
 coverage.xml
 coverage_html_report
+*.pytest_cache
 
 # OS generated files #
 ######################
@@ -90,7 +91,6 @@ scikits
 
 # Unit / Performance Testing #
 ##############################
-.pytest_cache/
 asv_bench/env/
 asv_bench/html/
 asv_bench/results/
@@ -109,3 +109,4 @@ doc/tmp.sv
 doc/source/styled.xlsx
 doc/source/templates/
 env/
+doc/source/savefig/

ci/build_docs.sh

@@ -10,11 +10,11 @@ echo "inside $0"
 
 git show --pretty="format:" --name-only HEAD~5.. --first-parent | grep -P "rst|txt|doc"
 
-if [ "$?" != "0" ]; then
-    echo "Skipping doc build, none were modified"
-    # nope, skip docs build
-    exit 0
-fi
+# if [ "$?" != "0" ]; then
+#     echo "Skipping doc build, none were modified"
+#     # nope, skip docs build
+#     exit 0
+# fi
 
 
 if [ "$DOC" ]; then

ci/requirements-2.7_COMPAT.pip

@@ -1,4 +1,4 @@
 html5lib==1.0b2
-beautifulsoup4==4.2.0
+beautifulsoup4==4.2.1
 openpyxl
 argparse

ci/requirements-3.6_NUMPY_DEV.build.sh

@@ -12,8 +12,7 @@ PRE_WHEELS="https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf
 pip install --pre --upgrade --timeout=60 -f $PRE_WHEELS numpy scipy
 
 # install dateutil from master
-# pip install -U git+git://github.com/dateutil/dateutil.git
-pip install dateutil
+pip install -U git+git://github.com/dateutil/dateutil.git
 
 # cython via pip
 pip install cython

ci/requirements-optional-conda.txt

@@ -1,4 +1,4 @@
-beautifulsoup4
+beautifulsoup4>=4.2.1
 blosc
 bottleneck
 fastparquet

ci/requirements-optional-pip.txt

@@ -1,6 +1,6 @@
 # This file was autogenerated by scripts/convert_deps.py
 # Do not modify directly
-beautifulsoup4
+beautifulsoup4>=4.2.1
 blosc
 bottleneck
 fastparquet

doc/cheatsheet/Pandas_Cheat_Sheet.pdf

@@ -32,8 +32,9 @@ Bug reports and enhancement requests
 
 Bug reports are an important part of making *pandas* more stable. Having a complete bug report
 will allow others to reproduce the bug and provide insight into fixing. See
-`this stackoverflow article <https://stackoverflow.com/help/mcve>`_ for tips on
-writing a good bug report.
+`this stackoverflow article <https://stackoverflow.com/help/mcve>`_ and
+`this blogpost <http://matthewrocklin.com/blog/work/2018/02/28/minimal-bug-reports>`_
+for tips on writing a good bug report.
 
 Trying the bug-producing code out on the *master* branch is often a worthwhile exercise
 to confirm the bug still exists. It is also worth searching existing bug reports and pull requests
@@ -246,16 +247,16 @@ changes in this branch specific to one bug or feature so it is clear
 what the branch brings to *pandas*. You can have many shiny-new-features
 and switch in between them using the git checkout command.
 
-To update this branch, you need to retrieve the changes from the master branch::
+When creating this branch, make sure your master branch is up to date with
+the latest upstream master version. To update your local master branch, you
+can do::
 
-    git fetch upstream
-    git rebase upstream/master
+    git checkout master
+    git pull upstream master --ff-only
 
-This will replay your commits on top of the latest pandas git master.  If this
-leads to merge conflicts, you must resolve these before submitting your pull
-request.  If you have uncommitted changes, you will need to ``stash`` them prior
-to updating.  This will effectively store your changes and they can be reapplied
-after updating.
+When you want to update the feature branch with changes in master after
+you created the branch, check the section on
+:ref:`updating a PR <contributing.update-pr>`.
 
 .. _contributing.documentation:
 
@@ -293,12 +294,9 @@ Some other important things to know about the docs:
   overviews per topic together with some other information (what's new,
   installation, etc).
 
-- The docstrings follow the **Numpy Docstring Standard**, which is used widely
-  in the Scientific Python community. This standard specifies the format of
-  the different sections of the docstring. See `this document
-  <https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt>`_
-  for a detailed explanation, or look at some of the existing functions to
-  extend it in a similar manner.
+- The docstrings follow a pandas convention, based on the **Numpy Docstring
+  Standard**. Follow the :ref:`pandas docstring guide <docstring>` for detailed
+  instructions on how to write a correct docstring.
 
 - The tutorials make heavy use of the `ipython directive
   <http://matplotlib.org/sampledoc/ipython_directive.html>`_ sphinx extension.
@@ -967,32 +965,6 @@ Now you can commit your changes in your local repository::
 
     git commit -m
 
-Combining commits
------------------
-
-If you have multiple commits, you may want to combine them into one commit, often
-referred to as "squashing" or "rebasing".  This is a common request by package maintainers
-when submitting a pull request as it maintains a more compact commit history.  To rebase
-your commits::
-
-    git rebase -i HEAD~#
-
-Where # is the number of commits you want to combine.  Then you can pick the relevant
-commit message and discard others.
-
-To squash to the master branch do::
-
-    git rebase -i master
-
-Use the ``s`` option on a commit to ``squash``, meaning to keep the commit messages,
-or ``f`` to ``fixup``, meaning to merge the commit messages.
-
-Then you will need to push the branch (see below) forcefully to replace the current
-commits with the new ones::
-
-    git push origin shiny-new-feature -f
-
-
 Pushing your changes
 --------------------
 
@@ -1048,15 +1020,51 @@ release.  To submit a pull request:
 #. Click ``Send Pull Request``.
 
 This request then goes to the repository maintainers, and they will review
-the code. If you need to make more changes, you can make them in
-your branch, push them to GitHub, and the pull request will be automatically
-updated.  Pushing them to GitHub again is done by::
+the code. 
+
+.. _contributing.update-pr:
 
-    git push -f origin shiny-new-feature
+Updating your pull request
+--------------------------
+
+Based on the review you get on your pull request, you will probably need to make
+some changes to the code. In that case, you can make them in your branch, 
+add a new commit to that branch, push it to GitHub, and the pull request will be
+automatically updated.  Pushing them to GitHub again is done by::
+
+    git push origin shiny-new-feature
 
 This will automatically update your pull request with the latest code and restart the
 :ref:`Continuous Integration <contributing.ci>` tests.
 
+Another reason you might need to update your pull request is to solve conflicts
+with changes that have been merged into the master branch since you opened your
+pull request. 
+
+To do this, you need to "merge upstream master" in your branch::
+
+    git checkout shiny-new-feature
+    git fetch upstream
+    git merge upstream/master
+
+If there are no conflicts (or they could be fixed automatically), a file with a
+default commit message will open, and you can simply save and quit this file.
+
+If there are merge conflicts, you need to solve those conflicts. See for
+example at https://help.github.com/articles/resolving-a-merge-conflict-using-the-command-line/
+for an explanation on how to do this.
+Once the conflicts are merged and the files where the conflicts were solved are
+added, you can run ``git commit`` to save those fixes.
+
+If you have uncommitted changes at the moment you want to update the branch with
+master, you will need to ``stash`` them prior to updating (see the
+`stash docs <https://git-scm.com/book/en/v2/Git-Tools-Stashing-and-Cleaning>`__).
+This will effectively store your changes and they can be reapplied after updating.
+
+After the feature branch has been update locally, you can now update your pull
+request by pushing to the branch on GitHub::
+
+    git push origin shiny-new-feature
 
 Delete your merged branch (optional)
 ------------------------------------