René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"fill_between,  step='post' and NaN","articleBody":"Off-by-one error if using `fill_between`, `step='post'`\r\n\r\n\u003c!--A minimum code snippet required to reproduce the bug.\r\nPlease make sure to minimize the number of dependencies required, and provide\r\nany necessary plotted data.\r\nAvoid using threads, as Matplotlib is (explicitly) not thread-safe.--\u003e\r\n\r\n```python\r\nimport matplotlib.pyplot as plt\r\nimport pandas as pd\r\n\r\nfig = plt.figure(1)\r\nax = fig.add_subplot(111)\r\n\r\ndf = pd.DataFrame(index=pd.date_range(start='2000-01-01', periods=10, freq='1D'))\r\ndf['data'] = [1,2,3,-4,-5,-6,7,8,9,-10]\r\n\r\ndf.plot(ax=ax, drawstyle='steps-post')\r\nax.fill_between(df[df \u003e 0].index, df[df \u003e 0].values.flatten(), step='post')\r\n```\r\n\r\n**Actual outcome**\r\n\r\n![image](https://user-images.githubusercontent.com/145117/106748570-46cc4480-65da-11eb-8e38-83e2d4e02fc2.png)\r\n\r\n\r\n**Expected outcome**\r\n\r\nSome of the `df[df \u003e 0]` columns are not filled.\r\n\r\n**Matplotlib version**\r\n\u003c!--Please specify your platform and versions of the relevant libraries you are using:--\u003e\r\n  * Operating system:  Linux Kubuntu 20.04\r\n  * Matplotlib version (`import matplotlib; print(matplotlib.__version__)`): 3.3.1\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): Qt5Agg\r\n  * Python version: 3.8.5\r\n  * Jupyter version (if applicable): IPython 7.17.0\r\n","author":{"url":"https://github.com/mankoff","@type":"Person","name":"mankoff"},"datePublished":"2021-02-03T12:45:13.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":5},"url":"https://github.com/19444/matplotlib/issues/19444"}