Function 将一个函数嵌入另一个Jython

赋值的目标是使这两个函数一起工作，即将setPixeltoBlack调用到setPicturetoblack中

错误很明显：

The error was:'javainstance' object has no attribute '__call__'
Attribute not found.
You are trying to access a part of the object that doesn't exist.
Please check line 10 of /Users/tobiasdouglas/test3

主要问题：如何让计算机检查xpos和ypos是否存在两个变量？ 我写了一个psedoocode，上面显示了所需的内容

谢谢

import random
file=pickAFile()
picture=makePicture(file)
show(picture)
xpos = input("Enternumber")
ypos = input("Enternumber")

def setPixelToBlack(getPixel):
#if xpos and ypos = known
  setColor=(getPixel(picture,xpos,ypos),black)
#else
  #setcolor=(getPixels(picture), black)
  explore(picture)
  return

def setPictureToBlack(picture):
  for p in getPixels(picture):
    setPixelToBlack(p)

您可以使用specal value None，并检查变量是否为None以及是否为None

在代码中，xpo和ypo也是全局变量。您可以在函数中读取它们，但要更改其值，需要使用全局xpos、ypos语句

xpos = None
ypos = None

// some code that may set xpos or ypos

def setPixelToBlack(getPixel):
    if xpos is not None and ypos is not None:
        setColor=(getPixel(picture,xpos,ypos),black)
    // ...