Returns a DataFrame with the required format for 
	a pie plot

	Parameters:
	-----------
		n_labels : int
			Number of labels 
		mode : string
			Format for each item
				'abc' for alphabet columns
				'stocks' for random stock names

def pie(n_labels=5,mode=None):
	"""
	Returns a DataFrame with the required format for 
	a pie plot

	Parameters:
	-----------
		n_labels : int
			Number of labels 
		mode : string
			Format for each item
				'abc' for alphabet columns
				'stocks' for random stock names
	"""	
	return pd.DataFrame({'values':np.random.randint(1,100,n_labels),
						 'labels':getName(n_labels,mode=mode)})