local variable y referenced before assignment

Question

I am using python 2. I don't know what is wrong with my code, wrong message is "local variable y referenced before assignment". But variable y is assigned before referenced and there is no problem for variable x. Could you help to figure it out?

  def dyn_seq(n):
        C=[0,0,1,1]
        for i in range(4,n+1):
            z=C[i-1]+1
            if i % 2==0: 
                x=C[i/2]+1
            if i % 3==0:
                y=C[i/3]+1
            minu=min(x,y,z)
            C.append(minu)
        return C

And maybe your problem is duplicate. http://stackoverflow.com/questions/18002794/local-variable-referenced-before-assignment-in-python — WeiYuan, May 01 '16 at 16:34

score 1 · Accepted Answer · answered May 01 '16 at 16:36

1

You are doing a modulo division and your running variable starts at 4. 4 % 2 == 0 and x will be defined, while 4 % 3 != 0 and y is not defined, but used in the next line.

answered May 01 '16 at 16:36

Maximilian Peters

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Thanks! That is the exactly problem! – Liang Li May 01 '16 at 18:02

local variable y referenced before assignment

1 Answers1