I am trying to pass a non-mutable integer argument from one function to other defined functions; what is my mistake?

问题

Suppose I have a chain of function calls.

def func1( pick, arg1, arg2 ):
    if pick == 1:
        do stuff with arg1 and arg2
    elif pick == 2:
        do other stuff with arg1 and arg2 
    return stuff that got done

def func2( pick, arg1, arg2, arg3 ):
    if pick == 1:
        do stuff with arg1 and arg2 and arg3 
    elif pick == 2:
        do other stuff with arg1 and arg2 and arg3
    return stuff that got done

def func3( pick, func2, arg3 ):
    if pick == 1:
        do stuff with funcs and arg3
    elif pick == 2:
        do other stuff with funcs and arg3
    return stuff that done
etc ..

I was able to pass args from one function to another via SCIPY quad (numerical integration) so as to ensure that the args were not mutable. I was also able to pass args from one function to another via SCIPY minimize (optimization) in which the args are mutable. My trouble is in passing the non-mutable input pick from one function to another. If I were to place print(pick) as the first line of each defined function in the simplified example above, and if I were to call this chain of functions as

callme = func3( 2 , func2(pick = pick, args) , [6, 0.5] )

then my code would eventually spit out an error message that reads

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

but first it would do something like:

1
2
1
2
2 # (from pick = 2 in func3)
[6   0.5]

How/Why is this happening, and is it possible to send the input pick from one function to another in a chain of function calls?

Edit: My guess would be passing pick as an object of a class, or using kwargs, or passing pick as an unpackable tuple consisting of a single element; but I'm not sure if this is correct or how to implement this. Ideally, there is some operation I'm unaware of that is as simple as callme = func3( pick.func2 , func2, [6, 0.5] ). I've tried declaring pick as global, but this results in an error-message about a parameter being global.

回答1:

I removed pick as an input from every function but left it as a variable in the functino. I then placed the following code before the function chain to initialize pick.

def selectdist(pick):
    ## 1 for original representation
    ## 2 for normal representation on semilog(x) axis
    ## 3 for normal representation on linearly-spaced ln(x) axis
    return int(pick)

pickdist = selectdist(3) # choose 1 2 or 3

After the function chain, one run the function chain using a re-initialized pick. Since it no longer is an argument that is passed from the top of the function chain on down, the source of the bug is gone.

来源：https://stackoverflow.com/questions/42898612/i-am-trying-to-pass-a-non-mutable-integer-argument-from-one-function-to-other-de