René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Error reading png image from URL with imread in matplotlib 3.3","articleBody":"\u003c!--To help us understand and resolve your issue, please fill out the form to the best of your ability.--\u003e\r\n\u003c!--You can feel free to delete the sections that do not apply.--\u003e\r\n\r\n### Bug report\r\n\r\n**Bug summary**\r\n\r\nAfter upgrading to matplotlib 3.3, `imread` errors when reading in a png from a URL. This was working in 3.2.\r\n\r\n```python\r\nfrom matplotlib import image\r\nurl = 'https://github.com/hjnilsson/country-flags/raw/master/png250px/us.png'\r\nimage.imread(url)\r\n```\r\n\r\nResults in `UnsupportedOperation: seek`\r\n\r\nTraceback indicates error is from pillow. [Related Issue](https://github.com/imageio/imageio/issues/202)\r\n\r\n**Full Traceback**\r\n\r\n```\r\nUnsupportedOperation                      Traceback (most recent call last)\r\n\u003cipython-input-28-3cc23b6666a9\u003e in \u003cmodule\u003e\r\n----\u003e 1 image.imread(url)\r\n\r\n~/miniconda3/envs/mpl/lib/python3.8/site-packages/matplotlib/image.py in imread(fname, format)\r\n   1473             from urllib import request\r\n   1474             with urllib.request.urlopen(fname) as response:\r\n-\u003e 1475                 return imread(response, format=ext)\r\n   1476     with img_open(fname) as image:\r\n   1477         return (_pil_png_to_float_array(image)\r\n\r\n~/miniconda3/envs/mpl/lib/python3.8/site-packages/matplotlib/image.py in imread(fname, format)\r\n   1474             with urllib.request.urlopen(fname) as response:\r\n   1475                 return imread(response, format=ext)\r\n-\u003e 1476     with img_open(fname) as image:\r\n   1477         return (_pil_png_to_float_array(image)\r\n   1478                 if isinstance(image, PIL.PngImagePlugin.PngImageFile) else\r\n\r\n~/miniconda3/envs/mpl/lib/python3.8/site-packages/PIL/ImageFile.py in __init__(self, fp, filename)\r\n    115         try:\r\n    116             try:\r\n--\u003e 117                 self._open()\r\n    118             except (\r\n    119                 IndexError,  # end of data\r\n\r\n~/miniconda3/envs/mpl/lib/python3.8/site-packages/PIL/PngImagePlugin.py in _open(self)\r\n    651             # get next chunk\r\n    652 \r\n--\u003e 653             cid, pos, length = self.png.read()\r\n    654 \r\n    655             try:\r\n\r\n~/miniconda3/envs/mpl/lib/python3.8/site-packages/PIL/PngImagePlugin.py in read(self)\r\n    126             s = self.fp.read(8)\r\n    127             cid = s[4:]\r\n--\u003e 128             pos = self.fp.tell()\r\n    129             length = i32(s)\r\n    130 \r\n\r\nUnsupportedOperation: seek\r\n```\r\n\r\n\r\n\u003c!--A description of the expected outcome from the code snippet--\u003e\r\n\u003c!--If this used to work in an earlier version of Matplotlib, please note the version it used to work on--\u003e\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: macOS\r\n  * Matplotlib version: 3.3\r\n  * Matplotlib backend (`print(matplotlib.get_backend())`): MacOSX\r\n  * Python version: 3.8\r\n\r\n\u003c!--Please tell us how you installed matplotlib and python e.g., from source, pip, conda--\u003e\r\n\u003c!--If you installed from conda, please specify which channel you used if not the default--\u003e\r\n\r\n","author":{"url":"https://github.com/tdpetrou","@type":"Person","name":"tdpetrou"},"datePublished":"2020-07-30T16:39:18.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":23},"url":"https://github.com/18129/matplotlib/issues/18129"}