Python - plot only some labels

import pandas as pd
import matplotlib.pyplot as plt

headers = 'Date', 'Close', 'Open', 'High', 'Low'

text = '''27/12/2012 4541,79 4560,12 4560,75 4534,55
28/12/2012 4561,98 4541,79 4561,99 4536,47
31/12/2012 4579,85 4559,31 4579,85 4558,51
02/01/2013 4621,99 4588,08 4621,99 4586,71
03/01/2013 4642,08 4643,92 4654,52 4621,81
04/01/2013 4654,33 4648,85 4677,97 4642,69
07/01/2013 4652,74 4651,63 4663,86 4632,11'''.replace(',', '.')

# --- create data ---

data = [line.split() for line in text.split('\n')]

df = pd.DataFrame(data, columns=headers)
df['Close'] = df['Close'].astype(float)

# --- plot ---

ax = plt.plot(df['Close'], df['Date'])
ax[0].axes.set_yticks(df['Date'][::2]) # skip every 2nd label

#ax[0].axes.set_yticklabels(df['Date'][::2])

plt.show()