use format with tex fraction expression in matplotlib python

Question

I use matplotlib. I need to get xlabels like: [1/8,2/8,3/8,4/8..14/8]. I want to make it in a loop. Therefore, for better view I use TEX in Python. For rendering the fraction expression in the loop I use .format method. But it doesn't work properly. There is some conflict between using of {} in TEX and .format method. I tried to use double {} but it as well doesn't work.

import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
xax = ax.xaxis  # get x axis

labels = ['0']
for i in range(0, 14):
    labels.append(r'$\frac{}{8}$'.format(i)) # when trying to insert i an error occurs

xax.set_ticklabels(labels)

plt.show()

Answer 1

You need to escape the curled brackets ({) with another curled bracket.

r'$\frac{{{}}}{{8}}$'.format(i)

Here the inner most bracket pair in {{{}}} is used for formatting. The escape pair {{ is replaced by a single bracket during formatting. Hence r'$\frac{{{}}}{{8}}$'.format(1) will result in r'$\frac{1}{8}$', which is then a valid MathText string.