Alternatively you can put the legends beside the pie graph:
import matplotlib.pyplot as plt
import numpy as np
x = np.char.array(['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct', 'Nov','Dec'])
y = np.array([234, 64, 54,10, 0, 1, 0, 9, 2, 1, 7, 7])
colors = ['yellowgreen','red','gold','lightskyblue','white','lightcoral','blue','pink', 'darkgreen','yellow','grey','violet','magenta','cyan']
porcent = 100.*y/y.sum()
patches, texts = plt.pie(y, colors=colors, startangle=90, radius=1.2)
labels = ['{0} - {1:1.2f} %'.format(i,j) for i,j in zip(x, porcent)]
sort_legend = True
if sort_legend:
patches, labels, dummy = zip(*sorted(zip(patches, labels, y),
key=lambda x: x[2],
reverse=True))
plt.legend(patches, labels, loc='left center', bbox_to_anchor=(-0.1, 1.),
fontsize=8)
plt.savefig('piechart.png', bbox_inches='tight')
EDIT: if you want to keep the legend in the original order, as you mentioned in the comments, you can set sort_legend=False
in the code above, giving: