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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def scatter(n_categories=5,n=10,prefix='category',mode=None):
 	""" 	Returns a DataFrame with the required format for 	a scatter plot 	Parameters: 		n_categories : int 			Number of categories 		n : int 			Number of points for each category 		prefix : string 			Name for each category 		mode : string 			Format for each item 				'abc' for alphabet columns 				'stocks' for random stock names 	"""
	
	categories=[]
	for i in range(n_categories):
		categories.extend([prefix+str(i+1)]*n)
	return pd.DataFrame({'x':np.random.randn(n*n_categories),
						 'y':np.random.randn(n*n_categories),
						 'text':getName(n*n_categories,mode=mode),
						 'categories':categories})