为什么这个 python 代码不起作用（可能的语法错误？）答案

【问题标题】：Why is this python code not working (possible syntax error ?)为什么这个 python 代码不起作用（可能的语法错误？）
【发布时间】：2021-04-11 15:41:20
【问题描述】：

我是 python 新手，不明白为什么 goSouthWest 方法不适用于我的测试仪。这两个文件位于同一个文件夹中。出现的问题是“未定义 goSouthWest”。在 getPath 函数中调用 goSouthWest 函数时基本上是名称错误。有人可以告诉我我的代码有什么问题吗？测试者的内容如下。

测试人员：

from Map import Map  

map1 = Map(10, 10) 

print(map1.getPath(5, 5, 4, 1))

类：

import math

class Map:

    def __init__(self, row, column):
        self.row = row
        self.column = column

    def getPath(self, startRow, startCol, destRow, destCol):
        if startRow < 0 or startRow > self.row or startCol < 0 or startCol > self.column or destRow < 0 or destRow > self.row or destCol < 0 or destCol > self.column:
            raise ValueError("IllegalArgumentException")
        elif (startRow >= destRow and startCol >= destCol):
            path = goSouthWest(startRow, startCol, destRow, destCol)
        return path

    def goSouthWest(startRow, startCol, destRow, destCol): # goSouthWest method
        colDiff = startCol - destCol
        rowDiff = startRow - destRow
        if (colDiff > rowDiff) and (startRow != destRow):
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff > colDiff) and (startCol != destCol):
            startCol -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff > colDiff) and (startCol == destCol):
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (colDiff > rowDiff) and (startRow == destRow):
            startCol -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff == 0) and (colDiff == 0) and (destRow == 0) and (destCol == 0):
            startCol += 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        else:
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "

        if startCol != destCol and startRow != destRow:
            path = path + goSouthWest(startRow, startCol, destRow, destCol)

        return path

【问题讨论】：

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标签： python syntax nameerror undefined-function

【解决方案1】：

goSouthWest 中没有参数 self。此外，您应该将成员函数称为self.function()，例如path = self.goSouthWest(startRow, startCol, destRow, destCol)

【讨论】：

【解决方案2】：

你的代码应该是这样的：

import math

class Map:

    def __init__(self, row, column):
        self.row = row
        self.column = column

    def getPath(self, startRow, startCol, destRow, destCol):
        if startRow < 0 or startRow > self.row or startCol < 0 or startCol > self.column or destRow < 0 or destRow > self.row or destCol < 0 or destCol > self.column:
            raise ValueError("IllegalArgumentException")
        elif (startRow >= destRow and startCol >= destCol):
            path = goSouthWest(startRow, startCol, destRow, destCol)
        return path
                    # every method of a class must have a self argument
    def goSouthWest(self, startRow, startCol, destRow, destCol):
        colDiff = startCol - destCol
        rowDiff = startRow - destRow
        if (colDiff > rowDiff) and (startRow != destRow):
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff > colDiff) and (startCol != destCol):
            startCol -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff > colDiff) and (startCol == destCol):
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (colDiff > rowDiff) and (startRow == destRow):
            startCol -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        elif (rowDiff == 0) and (colDiff == 0) and (destRow == 0) and (destCol == 0):
            startCol += 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "
        else:
            startRow -= 1
            path = path + "(" + str(startRow) + "," + str(startCol) + ") "

        if startCol != destCol and startRow != destRow:
                          # methods of the class must be called with self
            path = path + self.goSouthWest(startRow, startCol, destRow, destCol)

        return path

【讨论】：