理解python中的变量作用域：一个练习程序

Question

这是一个我想尝试的练习，因为我觉得它很有趣。这个练习对于它正在做的事情来说是不必要的复杂，但是它试图作为实践来理解更复杂的python程序中的类、函数和变量行为

import os

class grabFile:
    fileObject = None
    def __init__(self, filename):
        self.fileObject = open(filename, "r")

    def getFile():
        return self.fileObject

class counter:
    fileC = None
    lineCount = 0
    def __init__(self, fileObject):
        self.fileC = fileObject

    def lineCounter(self):
        while True:
            self.fileC.readline()
            print(x)
        return lineCount


def Main():
    fileGrabber = grabFile("test.txt")
    fileObj = fileGrabber.getFile

    countObj = counter(fileObj)
    lineCount = countObj.lineCounter()
    print(lineCount)

Main()

但是，运行此命令时，出现以下错误：

Traceback (most recent call last):
  File "/home/may/Desktop/Tree/Programming/MiscProjects/TextAnalyzer.py", line 32, in <module>
Main()
  File "/home/may/Desktop/Tree/Programming/MiscProjects/TextAnalyzer.py", line 29, in Main
lineCount = countObj.lineCounter()
  File "/home/may/Desktop/Tree/Programming/MiscProjects/TextAnalyzer.py", line 19, in lineCounter
self.fileC.readline()
AttributeError: 'function' object has no attribute 'readline'
[Finished in 0.2s with exit code 1]

有人能帮我完全理解这个程序吗？而且，尽管这不是正确的提问地点，但对程序的样式或格式有何评论？尤其是“自我”的使用

谢谢你

Answer 1

我想你是想调用这个方法：

fileObj = fileGrabber.getFile()

您需要更改为实例方法：

def getFile(self):
    return self.fileObject

行计数器方法需要做一些工作：

def lineCounter(self):
    self.lineCount = len(self.fileC.readlines())
    return self.lineCount