Best Way To Check New-line-independent-identity Of 2 Files With Python

I tried filecmp.cmp(file1,file2) but it doesn't work since files are identically except for new line characters. Is there an option for that in filecmp or some other convenience

Solution 1:

I think a simple convenience function like this should do the job:

from itertools import izip

defareFilesIdentical(filename1, filename2):
    withopen(filename1, "rtU") as a:
        withopen(filename2, "rtU") as b:
            # Note that "all" and "izip" are lazy# (will stop at the first line that's not identical)returnall(myprint() and lineA == lineB
                       for lineA, lineB in izip(a.xreadlines(), b.xreadlines()))

Solution 2:

Try the difflib module - it provides classes and functions for comparing sequences.

For your needs, the difflib.Differ class looks interesting.

class difflib.Differ

This is a class for comparing sequences of lines of text, and producing human-readable differences or deltas. Differ uses SequenceMatcher both to compare sequences of lines, and to compare sequences of characters within similar (near-matching) lines.

See the differ example, that compares two texts. The sequences being compared can also be obtained from the readlines() method of file-like objects.

Solution 3:

Looks like you just need to check if files are same or not ignoring whitespace/newlines.

You can use a function like this

defdo_cmp(f1, f2):
    bufsize = 8*1024
    fp1 = open(f1, 'rb')
    fp2 = open(f2, 'rb')
    whileTrue:
        b1 = fp1.read(bufsize)
        b2 = fp2.read(bufsize)
        ifnot is_same(b1, b2):
            returnFalseifnot b1:
            returnTruedefis_same(text1, text2):
    return text1.replace("\n","") == text2.replace("\n","")

you can improve is_same so that it matches according to your requirements e.g. you may ignore case too.