How to change the xticks in matplotlib

Question

I am trying to rename the yticks in matplotlib.
With this code lines I get the first figure.

from matplotlib import pyplot as plt
incr = -2
fig = plt.figure(figsize=(4,2))
ax = fig.add_subplot(111)
ax.set_yticks([])

yy = [[0.1, 0.2, 0.4], [0.2,0.3, 0.5], [0.4, 0.3, 0.5]]
for i in range(len(yy)):
    incr += 2
    xx = list(range(len(yy[i])))
    xx = [x+incr for x in xx]
    ax.plot(xx, yy[i])
    ax.plot([incr,incr], [0,.3])

How could I change the xticks as in this figure

Answer 1

from matplotlib import pyplot as plt

incr = -2
fig = plt.figure(figsize=(4,2))
ax = fig.add_subplot(111)
ax.set_yticks([])
xlabel = []
yy = [[0.1, 0.2, 0.4], [0.2,0.3, 0.5], [0.4, 0.3, 0.5]]
for i in range(len(yy)):
    incr += 2
    xx = list(range(len(yy[i])))
    xx = [x+incr for x in xx]
    ax.plot(xx, yy[i])
    ax.plot([incr,incr], [0,.3])
    xlabel.append(incr)

ax.set_xticks(xlabel)
ax.set_xticklabels(['set 1', 'set 2', 'set 3'], rotation=45)

for label in ax.get_xticklabels():
    label.set_horizontalalignment('left')

Output: