Comparing two files using difflib in python

Question

I am trying to compare two files using difflib. After comparing I want to print "No Changes" if no difference detected. If difference is their in some lines. I want to print those line.

I tried like this:

with open("compare.txt") as f, open("test.txt") as g:
            flines = f.readlines()
            glines = g.readlines()
        d = difflib.Differ()
        diff = d.compare(flines, glines)
        print("\n".join(diff))

It will print the contents of the file if "no changes" are detected. But I want to print "No Changes" if there is no difference.

Have you looked at the answers to this question?

David C
– David C

2015-10-10 06:17:03 +00:00
Commented Oct 10, 2015 at 6:17 — David C
– David C, Commented Oct 10, 2015 at 6:17

David C · Accepted Answer · 2015-10-10 06:28:41Z

3

Check to see if the first character in each element has a + or - at the start (marking the line having changed):

with open("compare.txt") as f, open("test.txt") as g:
        flines = f.readlines()
        glines = g.readlines()
        d = difflib.Differ()
        diffs = [x for x in d.compare(flines, glines) if x[0] in ('+', '-')]
        if diffs:
            # all rows with changes
        else:
            print('No changes')

answered Oct 10, 2015 at 6:28

David C

7,5847 gold badges50 silver badges66 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Krishna Over a year ago

Thanks for ur help. But its printing nothing

Krishna Over a year ago

THANK YOU David, I got the result

Collectives™ on Stack Overflow

Comparing two files using difflib in python

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related