在__init __()python中打开文件 [英] Open file in __init__() python

问题描述

嘿，我遇到以下问题，我需要在__init__()中打开一个文件，并使用check函数来检查此文件行中的字符串/数字是否相同.如果不是，则应返回True；如果不是，则应返回False；如果没有更多行，则应返回None.我不知道文件中将有多少行.我的代码工作正常，测试人员给了我90％的费用，但是它说我不关闭文件，我理解为什么要说，但是不知道放在哪里.但是，如果我使用with打开它，它应该可以工作，但是我不知道如何使它那样工作.

Hey I have a following problem, I need to open a file in __init__(), and with check function I need to check if strings/numbers in rows of this file are the same or not. If they aren't it should return True if they are it should return False, and if there are no more lines None. I do not know how many lines are there going to be in the file. My code is working kind of, tester is giving me 90%, but it says I do not close the file, I understand why it is saying, but do not know where to put the close. However if I opened it with with it should be working but I do not know how to get it working that way.

我的代码:

class Program:
    def __init__(self, file_name):
        self.t = open(file_name, 'r')

    def check(self):
        row = self.t.readline()

        array = []

        for i in row.split():
            if i not in array:
                array.append(i)

        if row.split() == []:
            return None
        elif array == row.split():
            return True
        else:
            return False

"""
#testing

if __name__ == '__main__':
    u = Program('file.txt')
    z = True
    while z is not None:
        z = u.check()
        print(z)

"""

示例文件:

15 9 22
2014 2015 2014 2015
p py pyt pyth pytho python
ab ab ab ab ab

推荐答案

由于使用一种方法打开文件，然后使用另一种方法，因此无法使用该类内部的with语句.您可以添加一种方法来关闭文件，并让关闭成为调用者的问题.呼叫者常用的解决方案是使用contextlib.closing.全部放在一起...

Since you open the file in one method and use it an another, you can't use the with statement internal to the class. You can add a method to close the file and let the closing be the caller's problem. A popular solution to the caller is to use contextlib.closing. Putting it all together...

class Program:
    def __init__(self, file_name):
        self.t = open(file_name, 'r')

    def check(self):
        ...

    def close(self):
        if self.t:
            self.t.close()
            self.t = None


import contextlib
with contextlib.closing(Program('myfile.txt')) as program:
    program.check()

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