import matplotlib.pyplot as plt
# The slices will be ordered and plotted counter-clockwise.
labels = [r'Rayos X (88.4 %)', r'RMN en solucion (10.6 %)', 
r'Microscopia electronica (0.7 %)', r'Otros (0.3 %)']
sizes = [88.4, 10.6, 0.7, 0.3]
colors = ['yellowgreen', 'gold', 'lightskyblue', 'lightcoral']
patches, texts = plt.pie(sizes, colors=colors, startangle=90)

plt.legend(patches, labels, loc="best") # The Legend

# Set aspect ratio to be equal so that pie is drawn as a circle.
plt.axis('equal')
plt.tight_layout()
plt.show()