import sys def fact(x): ##print 'entered fact ', x if x==1: result= 1 else: result= fact (x-1)*x print 'leaving fact ', result return result def fact_tail_call(x,c): #print 'entered fact_ ', x, ' ', c if x==1: print c raise 'done' #result= c else: result= fact_ (x-1,c*x) print 'leaving fact_ ', result return result fact (200) fact_tail_call (200, 1)