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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"In linux, copying a tkinter font doubles its size when using Tk 8.6 and a hi-res screen.","articleBody":"# Bug report\n\n### Bug description:\n\n```python\n\u003e\u003e\u003e import tkinter\n\u003e\u003e\u003e from tkinter.font import Font\n\u003e\u003e\u003e root = tkinter.Tk()\n\u003e\u003e\u003e f1 = Font(name='TkDefaultFont', exists=True)\n\u003e\u003e\u003e f1.actual()\n{'family': 'Noto Sans', 'size': 20, 'weight': 'normal', 'slant': 'roman', 'underline': 0, 'overstrike': 0}\n\u003e\u003e\u003e f2 = f1.copy()\n\u003e\u003e\u003e f2.actual()\n{'family': 'Noto Sans', 'size': 40, 'weight': 'normal', 'slant': 'roman', 'underline': 0, 'overstrike': 0}\n\u003e\u003e\u003e f3 = f2.copy()\n\u003e\u003e\u003e f3.actual()\n{'family': 'Noto Sans', 'size': 80, 'weight': 'normal', 'slant': 'roman', 'underline': 0, 'overstrike': 0}\n\u003e\u003e\u003e f4 = f3.copy()\n\u003e\u003e\u003e f4.actual()\n{'family': 'Noto Sans', 'size': 160, 'weight': 'normal', 'slant': 'roman', 'underline': 0, 'overstrike': 0}\n```\nThe example above is from Ubuntu 24.04 running on an Asus Zenbook with EVO screen.  The display scaling from the system settings is the default, namely 200%.  This does not happen when the display scaling is 100%.\n\nNote that font f1 is already (more than) doubled in size, compared to what wish8.6 (built from 8.6.15 source) reports:\n```\n% info patchlevel\n8.6.15\n% font actual TkDefaultFont\n-family {Noto Sans} -size 9 -weight normal -slant roman -underline 0 -overstrike 0\n% font config TkDefaultFont\n-family sans-serif -size -12 -weight normal -slant roman -underline 0 -overstrike 0\n```\nThe negative value -12 means that the size is 12 pixels, as opposed to 12 points.  I think the intitial expansion being slightly more than a factor of 2 may be caused by rounding when converting pixels to points.\n\nNote that the behavior of Tk 9 is different.  Using wish9.0 on the same system produces:\n```\n% info patchlevel\n9.0.0\n% font actual TkDefaultFont\n-family {Noto Sans} -size 10 -weight normal -slant roman -underline 0 -overstrike 0\n% font config TkDefaultFont\n-family sans-serif -size 10 -weight normal -slant roman -underline 0 -overstrike 0\n```\nAlso, the pending new version of tkinter from #124156 does not have this doubling behavior when used with Tk 9.0.  (I have not tested the new tkinter with Tk 8.6, but I expect it to have the broken behavior since I don't think that the PR changes Font.copy.)\n\n\n### CPython versions tested on:\n\n3.12\n\n### Operating systems tested on:\n\nLinux","author":{"url":"https://github.com/culler","@type":"Person","name":"culler"},"datePublished":"2025-01-10T23:04:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":7},"url":"https://github.com/128719/cpython/issues/128719"}