Pascale's Triangle.py

#!/usr/bin/env python

import math,os,sys

def clear():
	os.system('cls' if os.name=='nt' else 'clear')

def init():
	clear()
	print "Pascale's Triangle\n"

def get_int(prompt):
	print prompt
	result = 0
	while result == 0:
		try:
			result = input("> ")
		except NameError:
			pass
	return result

def get_str(prompt):
	print prompt
	result = raw_input("> ")
	return result

def nCr(n,r):
	f = math.factorial
	return f(n)/(f(n-r)*f(r))
	
def gen_triangle(rows,delim=" "):
	ncr_triangle = ""
	int_triangle = ""
	for x in range(0,rows):
		ncr = ""
		result = ""
		for y in range(0,x+1):
			ncr = "%s%sC%s%s" % (ncr,x,y,delim)
			result = "%s%s%s" % (result,nCr(x,y),delim)
		ncr_triangle = "%s%s\n" % (ncr_triangle,ncr)
		int_triangle = "%s%s\n" % (int_triangle,result)
		
	return ncr_triangle, int_triangle

def print_formatted_triangle(triangle):
	rows = triangle.splitlines()
	formatted = []
	width = len(rows[len(rows)-1])
	for row in rows:
		if len(row) < width:
			spacing = " "*int((width-len(row))/2)
		else:
			spacing = ""
		row  = "%s%s%s" % (spacing,row,spacing)
		formatted.append(row)
	print "%s%d Rows\n" % (" "*int((width-len(str(len(rows)))-5)/2),len(rows))
	print "\n".join(formatted)
	print "\n"
	
def main():
	init()
	if len(sys.argv) > 1:
		rows = int(sys.argv[1])
	else:
		rows = get_int("Enter Number Of Rows")
	ncr_triangle, int_triangle = gen_triangle(rows)
	#print_formatted_triangle(ncr_triangle)
	print_formatted_triangle(int_triangle)
		
if __name__ == '__main__':
    main()