python常规方法实现数组的全排列

def perm(l):
 if(len(l)<=1):
 return [l]
 r=[]
 for i in range(len(l)):
 s=l[:i]+l[i+1:]
 p=perm(s)
 for x in p:
 r.append(l[i:i+1]+x)
 return r

if __name__=='__main__': 
 """ default param is list(1,2,3,4,5) """
 l=[]; 
 if(len(sys.argv)<=1): 
 """input=['%d' %(i) for i in xrange(1,6)]"""
 l=list((1,2,3,4,5))
 else:#input param looks like "2,3,4,5,6",no legal checks here.
 input=str(sys.argv[1])
 l=input.split(",") 
 for i in xrange(len(l)): 
 l[i] = int(l[i]) 
 print perm(l)