René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]: Inconsistent treatment of list of labels in `plot` when the input is a dataframe","articleBody":"### Bug summary\n\n`plt.plot` interprets a dataframe as a sequence of series to be plotted, one per column. Labels can be specified by setting `label` to a list of labels matching the number of columns. If the dataframe has only one column, though, the `label` argument is interpreted as a single label, instead of a list with one element.\n\n### Code for reproduction\n\n```python\nfrom matplotlib import pyplot as plt\r\nimport pandas as pd\r\nimport numpy as np\r\n\r\nx = np.arange(5)\r\ny = pd.DataFrame({'a': x, 'b': x + 1})\r\n\r\nplt.figure('double', clear=True)\r\nplt.plot(x, y, label=['A', 'B'])\r\nplt.legend() # -\u003e ok\r\n\r\nplt.figure('single', clear=True)\r\nplt.plot(x, y.drop('b', axis=1), label=['A'])\r\nplt.legend() # -\u003e legend label is \"['A']\"\r\n\r\nplt.show()\n```\n\n\n### Actual outcome\n\n\u003cimg width=\"592\" alt=\"immagine\" src=\"https://github.com/matplotlib/matplotlib/assets/9684110/aa6abbcc-dd05-459b-b4ae-acb8a0d2e998\"\u003e\r\n\n\n### Expected outcome\n\n\u003cimg width=\"573\" alt=\"immagine\" src=\"https://github.com/matplotlib/matplotlib/assets/9684110/4dd88c38-216d-446b-a8d4-de70e299f39e\"\u003e\r\n\n\n### Additional information\n\n_No response_\n\n### Operating system\n\nmacOS 14.2.1\n\n### Matplotlib Version\n\n3.8.2\n\n### Matplotlib Backend\n\nMacOSX\n\n### Python version\n\n3.12.1 | packaged by conda-forge | (main, Dec 23 2023, 08:01:35) [Clang 16.0.6 ]\n\n### Jupyter version\n\n_No response_\n\n### Installation\n\nconda","author":{"url":"https://github.com/Gattocrucco","@type":"Person","name":"Gattocrucco"},"datePublished":"2024-02-08T22:51:47.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":9},"url":"https://github.com/27762/matplotlib/issues/27762"}