Warning about (and auto-fixing) crowded labels

tight_layout() only ever reserves one text row per tick/label, so it has no way to notice an unrotated x tick label running into its neighbor, or a title wider than the axes it sits over – fixing that means picking a smaller font, rotating the labels, shortening the text, or widening the figure, a choice only the caller can make. By default it warns and names a concrete fix; tight_layout(auto_label_scale=True) picks the “smaller font” fix itself, for whichever text has a per-instance size to shrink (tick labels, an axes title, a group title – not a plain set_xlabel, which has none), down to a legibility floor.

import plotpress

departments = ["Customer Success", "Product Engineering", "Sales & Marketing",
               "Finance & Legal", "Human Resources", "Information Technology"]
headcount = [42, 68, 55, 19, 24, 31]

fig, ax = plotpress.subplots(figsize=(6.0, 4.0))
ax.bar(departments, headcount, color="#d62728")
ax.set_title("Default size -- warns about the overlap")
fig.tight_layout()

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/home/runner/work/plotpress/plotpress/docs/examples/axes_features/plot_27_auto_label_scale.py:24: UserWarning: tight_layout(): the 'Default size -- warns about the overlap'-titled axes's x tick labels are wider (~94px) than their average spacing (~92px) and may overlap -- try tick_params(axis='x', labelrotation=45) to angle them, tick_params(axis='x', labelsize=<smaller>) to shrink them, tight_layout(auto_label_scale=True) to shrink them automatically, or set_xticks(...) to thin them out.
  fig.tight_layout()

fig.tight_layout() above prints a UserWarning naming the overlap and how to fix it, but leaves the labels exactly as given – deciding the fix is the caller’s call, not tight_layout()’s to make silently. Asking for auto_label_scale=True instead makes that call automatically:

fig2, ax2 = plotpress.subplots(figsize=(6.0, 4.0))
ax2.bar(departments, headcount, color="#2ca02c")
ax2.set_title("auto_label_scale=True -- shrinks to fit")
fig2.tight_layout(auto_label_scale=True)

Live figure — pick a tool, then zoom, pan, point-pick or annotate. Nothing is active until a tool is selected.

View this figure’s Vega export ↗ — the raw JSON spec, rendered live by a real Vega engine.

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The same fix is also available as one call: tick_params(axis="x", labelrotation=...) (see the previous example) usually reads better for a grid of long category names – auto_label_scale is the option for whenever a smaller font is the better fix instead, or the fastest fix “make it warn until I have time to pick a look.”