customizing just one side of tick marks in matplotlib using spines

Question

I have a matplotlib horizontal bar drawn as follows:

import matplotlib.pyplot as plt
from numpy import *
from scipy import *
bars = arange(5) + 0.1
vals = rand(5)
print bars, vals
plt.figure(figsize=(5,5), dpi=100)
spines = ["bottom"]
ax = plt.subplot(1, 1, 1)
for loc, spine in ax.spines.iteritems():
  if loc not in spines:
    spine.set_color('none')
# don't draw ytick marks
#ax.yaxis.set_tick_params(size=0)
ax.xaxis.set_ticks_position('bottom')
plt.barh(bars, vals, align="center")
plt.savefig("test.png") 

This produces this image:

I wanted to only show the xaxis, which worked using spines, but now it plots these hanging tickmarks for the right-hand yaxis. How can I remove these? id like to keep the ytickmarks on the left hand side of the plot and make them face out (direction opposite to bars). I know that I can remove the ytickmarks altogether by uncommenting the line:

#ax.yaxis.set_tick_params(size=0)

but i want to keep the ytick marks only on the left hand side. thank you.

EDIT: I achieved a solution after some trial and error though i'm sure my solution is probably not the best way to do it, so please let me know what you think still. i found that i can do:

ax.spines["left"].axis.axes.tick_params(direction="outward") 

to set the tick mark direction. to get rid of the right y-axis ticks, i use:

ax.yaxis.set_ticks_position("left")

Murrhine

I wrote an answer of how to do something like this for another question: https://mcmap.net/q/861325/-matplotlib-top-bottom-ticks-different (not using spines though, so not a direct answer to this question, but maybe helpful for some people...) – Ly

Answer 1

you could simply use:

ax.tick_params(axis='y', direction='out')

this will orientate the ticks as you want. And:

ax.yaxis.tick_left()

this will not plot the right ticks

Archduchess

Answer 2

You can use:

ax.tick_params(top="off")
ax.tick_params(bottom="off")
ax.tick_params(right="off")
ax.tick_params(left="off")

Hanoverian