How to use cmp() function to compare 2 files?

[yinglcs@gmail.com]

Hi,

i have 2 files which are different (1 line difference):
$ diff groupresult2007 0226190027.xml groupresult2007 0226190027-2.xml
5c5
< x:22 y:516 w:740 h:120 area:
---

x:22 y:516 w:740 h:1202 area:

But when I use the cmp() function to compare 2 files, it return "1",

$ python Python 2.4.3 (#1, Oct 23 2006, 14:19:47)
[GCC 4.1.1 20060525 (Red Hat 4.1.1-1)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.

>>cmp("groupres ult200702261900 27.xml", "groupresult200 70226190027-2.xml")

1

Can you please tell me why? And how can I compare the content of 2
files in python?

[Dan Bishop]

Re: How to use cmp() function to compare 2 files?

On Feb 26, 10:09 pm, "ying...@gmail. com" <ying...@gmail. comwrote:

Hi,
>
i have 2 files which are different (1 line difference):
$ diff groupresult2007 0226190027.xml groupresult2007 0226190027-2.xml
5c5
< x:22 y:516 w:740 h:120 area:
---
>

x:22 y:516 w:740 h:1202 area:

>
But when I use the cmp() function to compare 2 files, it return "1",
>
$ python Python 2.4.3 (#1, Oct 23 2006, 14:19:47)
[GCC 4.1.1 20060525 (Red Hat 4.1.1-1)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.>>c mp("groupresult 20070226190027. xml", "groupresult200 70226190027-2.xml")
>
1
>
Can you please tell me why?

Because '.' '-' (character 25 of each string).

But this is comparing the filenames, which isn't what you want to do.

And how can I compare the content of 2
files in python?

Use the difflib module.

[yinglcs@gmail.com]

Re: How to use cmp() function to compare 2 files?

On Feb 26, 10:22 pm, "Dan Bishop" <danb...@yahoo. comwrote:

On Feb 26, 10:09 pm, "ying...@gmail. com" <ying...@gmail. comwrote:
>
>
>

Hi,

>

i have 2 files which are different (1 line difference):
$ diff groupresult2007 0226190027.xml groupresult2007 0226190027-2.xml
5c5
< x:22 y:516 w:740 h:120 area:
---

>

x:22 y:516 w:740 h:1202 area:

>

But when I use the cmp() function to compare 2 files, it return "1",

>

$ python Python 2.4.3 (#1, Oct 23 2006, 14:19:47)
[GCC 4.1.1 20060525 (Red Hat 4.1.1-1)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.>>c mp("groupresult 20070226190027. xml", "groupresult200 70226190027-2.xml")

>

1

>

Can you please tell me why?

>
Because '.' '-' (character 25 of each string).
>
But this is comparing the filenames, which isn't what you want to do.
>

And how can I compare the content of 2
files in python?

>
Use the difflib module.

Thanks, but from here:

http://doc.astro-wise.org/difflib.html

it said it is just for comparing 2 sequence of strings, not files.

How can I use that to compare content of 2 files?

[yinglcs@gmail.com]

Re: How to use cmp() function to compare 2 files?

On Feb 26, 10:53 pm, "ying...@gmail. com" <ying...@gmail. comwrote:

On Feb 26, 10:22 pm, "Dan Bishop" <danb...@yahoo. comwrote:
>
>
>

On Feb 26, 10:09 pm, "ying...@gmail. com" <ying...@gmail. comwrote:

>

Hi,

>

i have 2 files which are different (1 line difference):
$ diff groupresult2007 0226190027.xml groupresult2007 0226190027-2.xml
5c5
< x:22 y:516 w:740 h:120 area:
---

>

x:22 y:516 w:740 h:1202 area:

>

But when I use the cmp() function to compare 2 files, it return "1",

>

$ python Python 2.4.3 (#1, Oct 23 2006, 14:19:47)
[GCC 4.1.1 20060525 (Red Hat 4.1.1-1)] on linux2
Type "help", "copyright" , "credits" or "license" for more information.>>c mp("groupresult 20070226190027. xml", "groupresult200 70226190027-2.xml")

>

1

>

Can you please tell me why?

>

Because '.' '-' (character 25 of each string).

>

But this is comparing the filenames, which isn't what you want to do.

>

And how can I compare the content of 2
files in python?

>

Use the difflib module.

>

I try this:
f1 = open("f1",'r')
f2 = open("f2", 'r')


if (difflib.contex t_diff(f1.readl ines(), f2.readlines()) .len()
== 0):

But I get this error:
Traceback (most recent call last):
File "./scripts/regressionTest. py", line 72, in ?
runTest(savedPa gesDirectory, outputDir, expectedResultD ir,
failedDir);
File "./scripts/regressionTest. py", line 60, in runTest
getSnapShot(fil eName, testNo, outputDir, expectedResultD ir,
failedDir)
File "./scripts/regressionTest. py", line 30, in getSnapShot
if (difflib.contex t_diff(f1.readl ines(), f2.readlines()) .len() ==
0):
# no difference
else:
# files are different
AttributeError: 'generator' object has no attribute 'len'

Can you please help?

[Marc 'BlackJack' Rintsch]

Re: How to use cmp() function to compare 2 files?

In <1172553141.665 287.65280@8g200 0cwh.googlegrou ps.com>, yinglcs@gmail.c om
wrote:

File "./scripts/regressionTest. py", line 30, in getSnapShot
if (difflib.contex t_diff(f1.readl ines(), f2.readlines()) .len() ==
0):
# no difference
else:
# files are different
AttributeError: 'generator' object has no attribute 'len'
>
Can you please help?

The function returns a generator/iterator over the differences which has
no `len()` method. If you just want to know if two files are equal or not
use `filecmp.cmp()` . Read the docs about the `shallow` argument of that
function.

Ciao,
Marc 'BlackJack' Rintsch

[samuel.y.l.cheung@gmail.com]

Re: How to use cmp() function to compare 2 files?

On Feb 27, 12:07 am, Marc 'BlackJack' Rintsch <bj_...@gmx.net wrote:

In <1172553141.665 287.65...@8g200 0cwh.googlegrou ps.com>, ying...@gmail.c om
wrote:
>

File "./scripts/regressionTest. py", line 30, in getSnapShot
if (difflib.contex t_diff(f1.readl ines(), f2.readlines()) .len() ==
0):
# no difference
else:
# files are different
AttributeError: 'generator' object has no attribute 'len'

>

Can you please help?

>
The function returns a generator/iterator over the differences which has
no `len()` method. If you just want to know if two files are equal or not
use `filecmp.cmp()` . Read the docs about the `shallow` argument of that
function.
>
Ciao,
Marc 'BlackJack' Rintsch

Thanks. I use that before, it does not work for me, since it always
return 1, regardless if the file content of 2 files are different or
not.

[Jussi Salmela]

Re: How to use cmp() function to compare 2 files?

samuel.y.l.cheu ng@gmail.com kirjoitti:

On Feb 27, 12:07 am, Marc 'BlackJack' Rintsch <bj_...@gmx.net wrote:

>In <1172553141.665 287.65...@8g200 0cwh.googlegrou ps.com>, ying...@gmail.c om
>wrote:
>>

>> File "./scripts/regressionTest. py", line 30, in getSnapShot
>> if (difflib.contex t_diff(f1.readl ines(), f2.readlines()) .len() ==
>>0):
>> # no difference
>> else:
>> # files are different
>>AttributeErro r: 'generator' object has no attribute 'len'
>>Can you please help?

>The function returns a generator/iterator over the differences which has
>no `len()` method. If you just want to know if two files are equal or not
>use `filecmp.cmp()` . Read the docs about the `shallow` argument of that
>function.
>>
>Ciao,
> Marc 'BlackJack' Rintsch

>
Thanks. I use that before, it does not work for me, since it always
return 1, regardless if the file content of 2 files are different or
not.
>
>

I think you are mixing cmp and filecmp.cmp. They are two different beasts.

Cheers,
Jussi