Aligning rotated xticklabels with their respective xticks

ha='right' is not enough to visually align labels with ticks:

• For rotation=45, use both ha='right' and rotation_mode='anchor'
• For other angles, use a ScaledTranslation() instead

---

rotation_mode='anchor'

If the rotation angle is roughly 45°, combine ha='right' with rotation_mode='anchor':

ax.set_xticks(ticks)
ax.set_xticklabels(labels, rotation=45, ha='right', rotation_mode='anchor')

Or in matplotlib 3.5.0+, set ticks and labels at once:

ax.set_xticks(ticks, labels, rotation=45, ha='right', rotation_mode='anchor')

---

ScaledTranslation()

If the rotation angle is more extreme (e.g., 70°) or you just want more fine-grained control, anchoring won't work well. Instead, apply a linear transform:

ax.set_xticks(ticks)
ax.set_xticklabels(labels, rotation=70)

# create -5pt offset in x direction
from matplotlib.transforms import ScaledTranslation
dx, dy = -5, 0
offset = ScaledTranslation(dx / fig.dpi, dy / fig.dpi, fig.dpi_scale_trans)

# apply offset to all xticklabels
for label in ax.xaxis.get_majorticklabels():
    label.set_transform(label.get_transform() + offset)

An easy, loop-free alternative is to use the horizontalalignment Text property as a keyword argument to xticks[1]. In the below, at the commented line, I've forced the xticks alignment to be "right".

n=5
x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Long ticklabel %i' % i for i in range(n)]
fig, ax = plt.subplots()
ax.plot(x,y, 'o-')

plt.xticks(
        [0,1,2,3,4],
        ["this label extends way past the figure's left boundary",
        "bad motorfinger", "green", "in the age of octopus diplomacy", "x"], 
        rotation=45,
        horizontalalignment="right")    # here
plt.show()

(yticks already aligns the right edge with the tick by default, but for xticks the default appears to be "center".)

[1] You find that described in the xticks documentation if you search for the phrase "Text properties".

You can set the horizontal alignment of ticklabels, see the example below. If you imagine a rectangular box around the rotated label, which side of the rectangle do you want to be aligned with the tickpoint?

Given your description, you want: ha='right'

n=5

x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Ticklabel %i' % i for i in range(n)]

fig, axs = plt.subplots(1,3, figsize=(12,3))

ha = ['right', 'center', 'left']

for n, ax in enumerate(axs):
    ax.plot(x,y, 'o-')
    ax.set_title(ha[n])
    ax.set_xticks(x)
    ax.set_xticklabels(xlabels, rotation=40, ha=ha[n])

Rotating the labels is certainly possible. Note though that doing so reduces the readability of the text. One alternative is to alternate label positions using a code like this:

import numpy as np
n=5

x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Long ticklabel %i' % i for i in range(n)]


fig, ax = plt.subplots()
ax.plot(x,y, 'o-')
ax.set_xticks(x)
labels = ax.set_xticklabels(xlabels)
for i, label in enumerate(labels):
    label.set_y(label.get_position()[1] - (i % 2) * 0.075)

For more background and alternatives, see this post on my blog