写入以读写模式打开的文件，从而改变结构 [英] Writing to a file which is open in read and write mode altering the structure

问题描述

我有一个文本文件，其中包含以下内容:

I have a text file, which has the following, contents:

joe satriani is god 
steve vai is god
steve morse is god
steve lukather is god

我想用python编写代码，这将更改文件行，例如:

I wanted to write a code in python, which will change the file lines like:

joe satriani is god ,absolutely man ..
steve vai is god,absolutely man ..
steve morse is god,absolutely man ..
steve lukather is god,absolutely man ..

我曾经尝试过这样做一次，但没有得到理想的结果.因此，首先，我尝试编写代码，该代码只会在第一行的末尾附加绝对是男人".

I had tried doing such earlier once and I had not gotten the desired outcome. So, first I tried writing a code, which would just append "absolutely man" at the end of only the first line.

因此，以下是我的代码:

So, the following is my code:

jj = open('readwrite.txt', 'r+')

jj.seek(1)
n = jj.read()
print(" yiuiuiuoioio \n") #just for debugging
print(n)

f = n.split("\n" , n.count("\n")) #to see what I am getting
print(f)   #As it turns out read returns the whole content as a string
print(len(f[0])) # just for debugging
jj.seek(len(f[0])) #take it to the end of first line
posy = jj.tell() # to see if it actually takes it 
print(posy)
jj.write(" Absolutely ..man ")

但是在执行代码时，我的文件更改为以下内容:

But on executing the code, my file changes to the following:

joe satriani is god Absolutely ..man d
steve morse is god
steve lukather is god

第二行被覆盖.如何在一行的末尾附加到一个字符串?

The second line is being overwritten. How to append to one string at the end of one line?

我想到了以读取和追加模式打开文件，但是它将覆盖现有文件.我不想从该文件中读取字符串，并通过追加将其写入另一个文件.如何添加或更改文件的行?

I thought of opening the file in read and append mode but it would overwrite the existing file. I do not want to read strings from this file and write the into another file by appending. How to append or alter the lines of a file?

有没有包装的方法吗?

推荐答案

given_str = 'absolutely man ..'
text = ''.join([x[:-1]+given_str+x[-1] for x in open('file.txt')])
with open('file.txt', 'w') as file:
    file.write(text)

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