当我尝试在函数中使用脚本中的变量时出现错误

Question

I have a function:

def Hanoi(A):

    pegA=['disc0', 'disc1', 'disc2']

If I call the function

Hanoi(pegA)

(I am using Autodesk Maya)

I get this error: name 'pegA' is not defined

I was under the impression that you could use a variable from your script in a function? Can anyone explain to me why I am getting this error?

Thank you

Answer 1

pegA is defined in the function, but you are passing it as an argument to the function. Basically youre trying to call it before it has been defined

Answer 2

With this code:

def Hanoi(A):
    pegA=['disc0', 'disc1', 'disc2']

You've defined a function Hanoi , and when the function is run, a local variable pegA is created. When the function returns, pegA is destroyed because it's local

Then when you call the function:

Hanoi(pegA)

There's no pegA to pass into the function. It'll get created inside, but doesn't exist outside.

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What you can do is create pegA outside the function, and pass it in:

def Hanoi(A):
    print A  # pegA was assigned to A when you called the function

pegA=['disc0', 'disc1', 'disc2']
Hanoi(pegA)

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Lastly, as an aside, the general convention is to start functions with lowercase letters, reserving uppercase for class names.