On Apr 15, 8:04 am, Grant Edwards <inva...@invalid> wrote: > On 2009-04-15, Martin <mar...@marcher.name> wrote: > > > > > Hi, > > > On Mon, Apr 13, 2009 at 10:03 PM, Grant Edwards <inva...@invalid> wrote: > >> On 2009-04-13, SpreadTooThin <bjobrie...@gmail.com> wrote: > > >>> I want to compare two binary files and see if they are the same. > >>> I see the filecmp.cmp function but I don't get a warm fuzzy feeling > >>> that it is doing a byte by byte comparison of two files to see if they > >>> are they same. > > >> Perhaps I'm being dim, but how else are you going to decide if > >> two files are the same unless you compare the bytes in the > >> files? > > > I'd say checksums, just about every download relies on checksums to > > verify you do have indeed the same file. > > That's slower than a byte-by-byte compare. > > >> You could hash them and compare the hashes, but that's a lot > >> more work than just comparing the two byte streams. > > > hashing is not exactly much mork in it's simplest form it's 2 > > lines per file. > > I meant a lot more CPU time/cycles. > > -- > Grant Edwards grante Yow! Was my SOY LOAF left > at out in th'RAIN? It tastes > visi.com REAL GOOD!!
I'd like to add my 2 cents here.. (Thats 1.8 cents US) All I was trying to get was a clarification of the documentation of the cmp method. It isn't clear. byte by byte comparison is good enough for me as long as there are no cache issues. a check sum is not good because it doesn't guarantee that 1 + 2 + 3 == 3 + 2 + 1 a crc of any sort is more work than a byte by byte comparison and doesn't give you any more information. -- http://mail.python.org/mailman/listinfo/python-list
