CODEWITHSUNDEEP
pythonregex
CSJ
CSJ

Reputation: 2957

keep contents between one pattern to another pattern

I want to parse html contents and keep the contents from A to B ex:

some content1...
<!-- begin_here -->
some content2
<!-- end_here -->
some content3

will become

<!-- begin_here -->
some content2
<!-- end_here -->

Now, I use sed to do:

sed '/begin_here/,/end_here/!d' file.html > file2.html

However, I'd like to rewrite it using python for cross-platform purpose. I am not very familiar to regex in python. Could give me some hints to do this? Thanks a lot :)

Upvotes: 0

Views: 85

Answers (2)

iruvar
iruvar

Reputation: 23364

Use multiline regex

import re
pat = re.compile('''^<!-- begin_here -->.*?<!-- end_here -->$''', 
                 re.DOTALL + re.MULTILINE)

with open("file.txt") as f:
    print pat.findall(f.read())

Upvotes: 2

jadkik94
jadkik94

Reputation: 7068

You can do it without regular expressions, like so:

add_next = False # Do not add lines
# Until you encounter the first "start_here", which sets it to True
with open("file1.html", "r") as in_file:
    with open("file2.html", "w") as out_file:
        for line in in_file:
            if "end_here" in line: # or line.startswith("end_here") for example
                add_next = False
            if add_next:
                out_file.write(line)
            if "begin_here" in line:
                add_next = True

Upvotes: 2

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