René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"[Bug]:  Line2D.set_linestyle treats dash pattern with None onoffseq as dashed","articleBody":"### Bug summary\r\n\r\nThe logic for setting linestyle using a dash tuple, i.e. `(offset, onoffseq)`, does not properly handle the case where `onoffseq` is `None`.\r\n\r\n### Code for reproduction\r\n\r\n```python\r\nprint(mpl.lines.Line2D([], [], linestyle=(0, None)).get_linestyle())\r\n```\r\n\r\n\r\n### Actual outcome\r\n\r\n`'--'`\r\n\r\n### Expected outcome\r\n\r\nIdeally, dash values would roundtrip, so the return would be `(0, None)`. Even when the dash sequence is not `None`, a lot of information is lost when this property is queried.\r\n\r\nBut more narrowly, `(0, None)` draws a solid line, so the return value should be `'-'`.\r\n\r\n### Additional information\r\n\r\nThe main consequence here is that the line's capstyle appears to conditionally read from `solid_capstyle` or `dash_capstyle` depending on the `get_linestyle` return value.\r\n\r\n### Matplotlib Version\r\n\r\n3.5.2","author":{"url":"https://github.com/mwaskom","@type":"Person","name":"mwaskom"},"datePublished":"2022-07-16T21:18:31.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/23437/matplotlib/issues/23437"}