python split string but keep delimiter

Question

In python I can easily read a file line by line into a set, just be using:

file = open("filename.txt", 'r')
content = set(file)

each of the elements in the set consists of the actual line and also the trailing line-break.

Now I have a string with multiple lines, which I want to compare to the content by using the normal set operations.

Is there any way of transforming a string into a set just the same way, such, that it also contains the line-breaks?

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Edit:

The question "In Python, how do I split a string and keep the separators?" deals with a similar problem, but the answer doesn't make it easy to adopt to other use-cases.

import re
content = re.split("(\n)", string)

doesn't have the expected effect.

Answer 1

The str.splitlines() method does exactly what you want if you pass True as the optional keepends parameter. It keeps the newlines on the end of each line, and doesn't add one to the last line if there was no newline at the end of the string.

text = "foo\nbar\nbaz"
lines = text.splitlines(True)
print(lines) # prints ['foo\n', 'bar\n', 'baz']

Answer 2

Here's a simple generator that does the job:

content = set(e + "\n" for e in s.split("\n"))

This solution adds an additional newline at the end though.