在没有用户输入的情况下替换/删除打开的文本文件中的子字符串（Python 3）

Question

How to use Python methods for replacing substrings (or deleting part of string) in an manually opened .txt file. Text file is already opened by the user and python script should replace substring in that file with space (or delete it, whatever is easier).

The string text file looks like this (it was part of the website and it can have multiple lines, but I put only first line for simplicity):

<tr><td>Subtitle</td><td><div class="Current temperature"><!-- here -- <!-- here2 --><div class="London"></div></div><div class="here3"></div><div class="Current temperature"><!-- here4 <!-- /react-text --><div class="Paris"></div></div></td></tr>

The final result should be in two lines:

London
Paris

I've already searched a lot of topics here, a lot of them assumes user input of the string that should be replaced and another input for the new string.

This little script is not of that type, it should already contain the substring to be replaced (without user input), so this parts:

1. <tr><td>Subtitle</td><td><div class="Current temperature"><!-- here -- <!-- here2 --><div class="
2. "></div></div><div class="here3"></div><div class="Current temperature"><!-- here4 <!-- /react-text --><div class="
3. "></div></div></td></tr>

and it should do it automatically when run. I also have problems with quotation marks and html tags so I get syntax errors often.

On other topics about this theme I found this and tried this code:

file = open("C:/Users/blue11440/Desktop/example-text-file.txt", "r")
str = file.readlines()

x = str.replace("<tr><td>Subtitle</td><td><div class="Current temperature"> 
<!-- here -- <!-- here2 --><div class="", "")

Among other errors I get this:

AttributeError: 'list' object has no attribute 'replace'
AttributeError: '_io.TextIOWrapper' object has no attribute 'replace'

I tried replace, delete, remove methods with little succes, is there any better way?

Answer 1

For your last problem: file.readlines() returns a list which contains an element for each line.

.replace() is a string (!) method. So try to iterate over the list:

for line in file.readlines():
    line.replace(....)

Edit: I think you have a problem with the " in the string: str.replace("Subtitle

Use single quotes to avoid this: str.replace('Subtitle