Re: mystery string code - help!

[Dan M]

> As a newbie Pythoner, I understand [] -1] but would some tell me how
> '::' does its magic?
> 
> Uncle Ben

The -1 is the "stride" or "step" argument. It's described at 
http://docs.python.org/release/2.3.5/whatsnew/section-slices.html

Dan
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Python 2.3.4, Berkeley db 1.85, db file format not recognized

[Dan M]

I'm working on a script that will interface with sendmail on my FreeBSD
box. I'm trying to read my access.db file (yes, it's for a quick and dirty
SMTP-after-POP application). I'm trying:

import bsddb
bsddb.hashopen("access.db")

but I get:
bsddb._db.DBInvalidArgError: (22, 'Invalid argument -- access.db: unexpected 
file type or format')

This suggests to me that my bsddb is too new. I really don't want to
rebuild sendmail with a more current db, as I'm afraid of breaking
sendmail. Any suggestions on how to read this file?
 
FWIW, "file access.db" returns "access.db: Berkeley DB 1.85 (Hash, version
2, native byte-order)"

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Re: Python 2.3.4, Berkeley db 1.85, db file format not recognized

[Dan M]

On Wed, 26 Oct 2005 14:23:49 -0500, skip wrote:

> 
> Dan> import bsddb
> Dan> bsddb.hashopen("access.db")
> 
> Dan> but I get:
> Dan> bsddb._db.DBInvalidArgError: (22, 'Invalid argument -- access.db: 
> unexpected file type or format')
> 
> Dan>  Any suggestions on how to read this file?
>  
> See if the bsddb185 module  is available:

It is, and it works. Thanks so much!

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Building 2.4.2 on OpenBSD 3.8

[Dan M]

I've been working with python 2.2.3 for the last couple of weeks, but
would like to move up to 2.4. I grabbed the 2.4.2 tarball and attempted to
install, but I get:

gcc -pthread -c -fno-strict-aliasing -DNDEBUG -g -O3 -Wall -Wstrict-prototypes 
-I. -I./Include  -DPy_BUILD_CORE -o Modules/python.o Modules/python.c
In file included from /usr/include/sys/select.h:38,
 from Include/pyport.h:116,
 from Include/Python.h:55,
 from Modules/python.c:3:
/usr/include/sys/event.h:53: error: syntax error before "u_int"
/usr/include/sys/event.h:55: error: syntax error before "u_short"
*** Error code 1

Stop in /usr/local/src/Python-2.4.2.

immediately upon running "make". I took at look at event.h to see if I
could find and fix the problem, but the error isn't immediately apparent
to me.

Has anyone successfully built 2.4.2 on OpenBSD? If so, how did you do it?

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Re: query a port

[Dan M]

On Sat, 29 Oct 2005 20:21:20 -0700, eight02645999 wrote:

> hi
> in python, how do one query a port to see whether it's up or not?
> thanks

I'm an absolute beginner, but let's see if I can help. Assuming you want
to check a port on another machine,

import socket
port=25 # Port we want to test
host=machine.to.test# Either IP address or FQDN
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
try:
s.connect((host, port)) 
print "We made the connection"
except socket.error:
print "Sorry, that port is not open"
s.close

Does that help?

Dan
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Re: query a port

[Dan M]

On Sat, 29 Oct 2005 23:21:16 -0700, eight02645999 wrote:

> thanks alot!
> that's all there is to it..so it's just a simple connect.

If all you want to do is check that the given port is open on the given
host, that's it. I tried it on my local box. When connecting to port 25,
it made the connection fine. Trying to connect to port 26 raised a
socket.error.

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Re: Using Which Version of Linux

[Dan M]

On Sat, 05 Nov 2005 04:26:38 -0600, blahman wrote:

> ok, i m going to use Linux for my Python Programs, mainly because i 
> need to see what will these fork() and exec() do. So, can anyone tell 
> me which flavour of linux i should use, some say that Debian is more 
> programmer friendly, or shold i use fedora, or Solaris. Because these 
> three are the only ones i know of that are popular and free.

Personally I would recommend staying away from Fedora unless you have a
friend who is well-versed in it and willing to help. I like the
distributin ok (I run it on the laptop I'm writing this from) but it uses
RPMs for package distribution, and the rpm tools don't know how to
automatically downloaded dependencies like yum or apt do. Because of that
I have to say that the RPM package tools suck quite badly.

Debian and SUSE are both pretty good choices.
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Timeout in urllib2

[Dan M]

I'm writing a system monitor script that needs to load web pages. I'm
using urllib2.urlopen to get the pages, and I'm attempting to set the
timeout value using socket.defaulttimeout.

Specifically, I'm calling socket.defaultttimeout(10), then calling
urllib2.urlopen to fetch a web page that never gets delivered. My code
waits about 30 seconds before terminating.

I am about to add threading to my app so that delays on a few servers
won't be a critical issue, but I'd still like to understand why the call
to socket.defaulttimeout doesn't affect the timeout on my urlopen calls.

My code follows.

#!/usr/local/bin/python
import socket, time

socket.setdefaulttimeout(10)
import urllib2

def doHttpTest():
url = "http://url.that.never.returns";
t_start = time.time()
if httptest(url):
print "Error on site ", url
t_end = time.time()
t_diff = t_end - t_start

def httptest(url):
timeout = 10
socket.setdefaulttimeout(timeout)
try:
req = urllib2.Request(url)
urllib2.urlopen(req)
except urllib2.HTTPError, e:
if e.code == 401:
return 1
elif e.code == 404:
return 1
elif e.code == 503:
return 1
else:
return 1
except urllib2.URLError, e:
return 1
else:
return 0



if __name__ == '__main__':
try:
doHttpTest()
except KeyboardInterrupt:
print "Exiting..."


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Re: how to handle two forms in cgi?

[Dan M]

>   My question is: How let these two form works together? I try to use
> two codes for these two forms, e.g. Login.py for login form and
> search.py for search form. But when user input data in search form and
> click its submit button, it just comes back to login form. Second form
> doesn't work.
> 
> Any help is appriciated!

It sounds like the "action" attribute in the 2nd form's  tag is not
pointing to search.py.

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Re: Python web publishing framework like Cocoon?

[Dan M]

> Is there a Python web publishing framework like Cocoon?
> 
> I found Maki  but it was last updated in 
> 2003 and its author says that he doesn't want to make another release...

How about:
http://www.cherrypy.org/
http://www.turbogears.org/
http://www.djangoproject.com/
http://karrigell.sourceforge.net/

just to name a few of my favorites. Take a look at
http://wiki.python.org/moin/WebProgramming for a more complete list.
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Re: How do I pass a variable to os.popen?

[Dan M]

On Mon, 31 Oct 2011 13:16:25 -0700, extraspecialbitter wrote:


> cmd = 'ethtool %interface'

Do you perhaps mean:

cmd = 'ethtool %s' % (interface, )
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Newbie: executing a system command from my Python app

[Dan M]

I'm writing a Python replacement for a particularly ugly shell script. we
are running mimedefang on our mail server, moving spam and virus messages
to a quarantine directory. This little python script successfully chdir's
to the quarantine directory, identifies all of the quarantine
subdirectories for yesterday's messages, and stuffs them into a tar file
in an archive directory. I then want to delete for successfully tarred
files and the subdirs they live in.

By way of further explanation, quarantined messages get broken into files
named ENTIRE_MESSAGE, HEADERS, RECIPIENTS, SENDER, and SENDMAIL-QID, and
get stored in subdirectories named qdir--MM-DD-hh.mm.ss-nnn, where
Y-M-D is the date received, hms is time received, and nnn is to allow for
up to 10 messages to quarantined any given second.

I know I can do this by descending into the directories I've identified
and unlink()ing each of the files, but I'd like to take a shortcut like:
"retval = os.system('rm -rf /var/spool/MD-Quarantine/qdir-%s*' %
(dateYest))" and indeed code written that executes without any errors.
Unfortunately it also leaves a bunch of qdir-2005-12-11-* files sitting
around when I run it on 12-11.

Have I overlooked some basic operation of the os.system() call? From all
I've seen in the online docs and O'Reilly's "Programming Python" it looks
like it should be working.

Here's my complete script:
#!/usr/local/bin/python

import glob, os, tarfile, time, datetime
DATE_FMT = "%Y-%m-%d"
filelist = []

yest = datetime.date.today() + datetime.timedelta(days = -1)
dateYest = yest.strftime(DATE_FMT)

os.chdir("/var/spool/MD-Quarantine")

try:
tar = tarfile.open("/usr/local/archives/MD-Q/%s.tar.gz" % (dateYest), 
"w:gz")
for file in glob.glob("qdir-%s*" % (dateYest)):
tar.add(file)
filelist.append(file)
tar.close()
except TarError:
print "The quarantine file archiving program threw a TarError 
exception"exit()

cmd = "rm -rf /var/spool/MD_Quarantine/qdir-%s*" % (dateYest)
print "About to execute ", cmd
retval = os.system(cmd)

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Re: Newbie: executing a system command from my Python app

[Dan M]

On Mon, 12 Dec 2005 13:25:14 -0800, Dan M wrote:

> I'm writing a Python replacement for a particularly ugly shell script. we
> are running mimedefang on our mail server, moving spam and virus messages
> to a quarantine directory. This little python script successfully chdir's
> to the quarantine directory, identifies all of the quarantine
> subdirectories for yesterday's messages, and stuffs them into a tar file
> in an archive directory. I then want to delete for successfully tarred
> files and the subdirs they live in.

Never mind - the flaw was in how I was building the command to be executed
by os.system. It's working fine now.

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Re: Newbie: executing a system command from my Python app

[Dan M]

> Few points points:
> 
> 1. Generally: I would try to minimize system calls. They make your code less
> portable.

Excellent point. In this case the app will never live anywhere other than
one specific FreeBSD machine, but I do appreciate the value of the advice
anyway. Therefore...

> 2. Look into the "shutil" module for recursive
deletion. 
> 3. Use os.path
> to construct paths. Try to avoid, for example,
> "c:\blah\blah" on dos, '/blah/blah' on unix, etc.

Have done so. Thanks for pointing out the shutils module! I keep finding
more and more excellent modules available. Do we have a Python equivalent
to Perl's CPAN?

> 4. If you only have one argument, you don't need a tuple
> for string formatting. 
> 5. "(dateYest)" is not a tuple anyway--the parentheses are
> superfluous 6. Single item tuples can be created with "(anitem,)"
> (notice the comma).

That helps. I had somehow gotten the mistaken idea that string formatting
always needed a tuple, and overlooked the trailing comma. I've applied
that correction to several of my other Python scripts as well.


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Re: Simple (?) question about print statement

[Dan M]

On Wed, 14 Dec 2005 15:27:58 -0800, TY wrote:

> So I guess then my next question is why does adding comma to print
> statement cause buffering, but not when you don't have comma?

Because of the line buffering. If you don't have a comma at the end, the
print statement prints the numeric value and a newline, which signals the
end of the line.

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Re: how to get select label?

[Dan M]

On Wed, 14 Dec 2005 13:56:24 -0800, lli wrote:

> I build web application. So I use CGI. I need to show select text in
> the html page. Now I can only display select value such as '001'. But I
> need to display its text 'AAA'.
> 
> LLI

I'm a Python newbie, so by all means verify this answer with more
experienced folks. But what you're running into is a limitation of
HTML/HTTP/CGI. When your form contains a  element, the values that
get passed to the CGI are the VALUE elements. If you want to get, for
example, AAA then you would need to put AAA in the VALUE field.
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Newbie question - deleting records from anydbm database

[Dan M]

I've been Googling like a mad fiend and flipping through my hard-copy
Python books, but still haven't located the one little bit of info I need.

I've put together a simple SMTP-after-IMAP script that gets the authorized
IP info from the mail log (I know, it's not elegant but it works). All
works fine up until I go to scan the database of added IP addresses to
delete the old ones. The problem is, I don't know how to drop a record
from an anydbm database!

The database file in question is compatible with the database built using
"makemap hash imapauth < imapauth" - in fact, I'm using makemap to check
the file contents against what I'm expecting.

I'm adding records with code such as:
 db = anydbm.open(accessDbPath, "w")
 db[ipAddress] = str(time.time())

Now how can I go about deleting that record when it's too old?

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Re: Newbie question - deleting records from anydbm database

[Dan M]

>> Now how can I go about deleting that record when it's too old?
>> 
> (untested)
> 
> try
> 
>  del db[ipAddress]

Yep, that did it. Thanks!

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Re: doubt on csv file

[Dan M]

> here is what am trying to do, first am trying to open it in a read
> mode, and checking each row by row , if it is not found till my last
> row, i want to append it to the last row , so how should i do that.
> 
> file = open ('C:\some.csv','r')
> reader = csv.reader(file)
> for row in reader:
> print row
> 
> How can i update at the last row.

This newbie's idea is that you'd want to keep track of whether you'd found
the item you are looking for. If not found, close the file, reopen it
in append mode, and write the new row. For example:
 f = open ('C:\some.csv','r')
 rdr = csv.reader(file)
 found = 0
 for row in rdr:
 if row[0] == 'YYY': found = 1
 print row
 if found:
 print "No need to do anything more"
 else:
 f.close()
 f = open("c:\\some.csv", 'a')
 f.write("The new row data")
 f.close()

I am admittedly a newbie; I'm sure more experienced users will have more
efficient suggestions. Note that I did change "file" to f to avoid hiding
the "file" method and changed "reader" to rdr for the same reason. 

HTH
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Re: doubt on csv file

[Dan M]

On Thu, 15 Dec 2005 16:09:51 -0800, muttu2244 wrote:

> hey thanks a lot for that it worked .

Excellent! Glad to be of assistance :)
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Re: urlretrieve() questions

[Dan M]

> Pretty straight forward...but what I'm finding is if the
> url is pointing to a file that is not there, the server
> returns a file that's a web page displaying a 404 error. 
> 
> Anyone have any recommendations for handling this?

You're right, that is NOT documented in a way that's easy to find! 

What I was able to find is how to what you want using urllib2 instead of
urllib. I found an old message thread that touches on the topic:
http://groups.google.com/group/comp.lang.python/browse_thread/thread/3f02bee97a689927/88c7bfec87e18ba9?q=%22http+status%22+%2Burllib&rnum=3#88c7bfec87e18ba9
(also accessable as http://tinyurl.com/952dw). Here's a quick summary:
---

Ivan Karajas
Apr 28 2004, 11:03 pm   show options
Newsgroups: comp.lang.python
From: Ivan Karajas <[EMAIL PROTECTED]> - Find messages by this author
Date: Wed, 28 Apr 2004 23:03:54 -0800
Local: Wed, Apr 28 2004 11:03 pm
Subject: Re: 404 errors
Reply to Author | Forward | Print | Individual Message | Show original | Report 
Abuse

On Tue, 27 Apr 2004 10:46:47 +0200, Tut wrote:
> Tue, 27 Apr 2004 11:00:57 +0800, Derek Fountain wrote:

>> Some servers respond with a nicely formatted bit of HTML explaining the
>> problem, which is fine for a human, but not for a script. Is there some
>> flag or something definitive on the response which says "this is a 404
>> error"?

> Maybe catch the urllib2.HTTPError?

This kind of answers the question. urllib will let you read whatever it
receives, regardless of the HTTP status; you need to use urllib2 if you
want to find out the status code when a request results in an error (any
HTTP status beginning with a 4 or 5). This can be done like so:

import urllib2
try:
asock = urllib2.urlopen("http://www.foo.com/qwerty.html";)
except urllib2.HTTPError, e:
print e.code

The value in urllib2.HTTPError.code comes from the first line of the web
server's HTTP response, just before the headers begin, e.g. "HTTP/1.1 200
OK", or "HTTP/1.1 404 Not Found".

One thing you need to be aware of is that some web sites don't behave as
you would expect them to; e.g. responding with a redirection rather than a
404 error when you when you request a page that doesn't exist. In these
cases you might still have to rely on some clever scripting.
--

I hope that helps.

Dan
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Re: copying a file from windows file system to ext2 and ext3

[Dan M]

On Tue, 10 Jan 2006 15:59:01 -0800, muttu2244 wrote:

> hi all
> 
> could anybody please tell me how can i copy a file from windows file
> systems like FAT12, FAT16,FAT32 and NTFS to EXT2, and EXT3.
> Is their any function in python that we can do the above
> 
> Thanks in advance
> Yogi

I'm sure more experienced hands will add comments here, but I believe
that's strictly dependent upon having the correct filesystem drivers
available on the system in question. Once you've mounted a Windows-type
file system on Linux you can manipulate the files that live there just as
if they were created on a real OS :)

Dan
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Re: TSV to HTML

[Dan M]

> 1) in the code define a css
> 2) use a regex to extract the info between tabs

In place of this, you might want to look at
http://effbot.org/librarybook/csv.htm
Around the middle of that page you'll see how to use a delimiter other
than a comma

> 3) wrap the values in the appropriate tags and insert into table. 4)
> write the .html file
> 
> Thanks again for your patience,
> Brian

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os.link makes a copy, not a link

[Dan M]

I'm a little bit confused. According to the sources I've looked at on the
net, 
os.link('file1', 'file2')
should make a hard link from file1 to file2. But what I'm finding is that
it's actually making a copy. Am I forgetting a step or something?

Python 2.3.4 running on CentOS 4.3

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Re: Redirecting stdin/stdout to self

[Dan M]

>>> And if I'm reading it correctly, the Perl
>>> script's process starts tcpdump, but redirects its output to its own
>>> input, and reads it line by line.

And to clarify, what the Perl script is doing is redirecting the standard
error to standard out. STDIN is file handle 0, STDOUT is file handle 1,
and STDERR is file handle 2.

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Re: script to read emails and extract attachments from cron

[Dan M]

On Mon, 06 Feb 2006 10:57:23 -0800, [EMAIL PROTECTED] wrote:

> Hi:
> 
> I am looking for advice on the best way to set up a process to read
> incoming emails (from a normal unix mailbox on the same host)
> containing a gzipped telemetry attachment. I'd like the script to
> extract the attachment into a directory where another process will pick
> it up. I plan to run it every minute out of cron, so it would probably
> start by moving the mbox file to another name so that incoming emails
> and later instances of itself won't be affected.

You might want to take a look at
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/86675 and
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/86676

I'm using those two recipes for a project very similar to what you
described.

Dan
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Re: Code Feedback

[Dan M]

> 2) Anybody know how to alter the "while 1: pass" section to make the
> app stoppable?

That one I think I can help with! See below.

> while 1: pass

  try:
  while 1:
pass
  except KeyboardInterrupt:
  break


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Re: Parsing XML - Newbie help

[Dan M]

Hi

rh0dium wrote:
> I am relatively new to python and certainly new to XML parsing.  

Me too. However there are plenty of good docs/tutorials available to 
help with both XML and using it in Python.

For XML you may wish to look at http://www.w3schools.com/. It has a very 
accessible set of tutorials on XML and related technologies, which I 
find make it very quick to get up and running. For what you are trying 
to do you may wish to look at XPath, or ideally XQuery although I'm not 
sure there is an XQuery implementation in Python.

For Python and XML there is Mark Pilgrim's excellent chapter on Parsing 
XML with xml.dom.minidom 
(http://diveintopython.org/xml_processing/index.html).

The is also the PyXML project at Sourceforge 
(http://pyxml.sourceforge.net/). A list of useful links is maintained 
there (http://pyxml.sourceforge.net/topics/).

You may also wish to investigate resources at the Python XML SIG page 
(http://www.python.org/sigs/xml-sig/).

These are just some of the sources of information I am using. Hope this 
helps.

Cheers

Dan

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Re: I'm just not cut out for web programming, I guess :)

[Dan M]

On Wed, 17 May 2006 20:51:07 +, John Salerno wrote:

> Ok, I've tinkered with this thing for a while, and I keep fixing little 
> problems, but I always get a 500 Internal Server error when I go to this 
> site:
> 
> I don't necessarily even want help just yet, I'd like to figure it out 
> myself, but can someone at least tell me why I'm not getting helpful 
> feedback from the cgitb module? Am I using it wrong? The webpage just 
> displays the internal server error.
> 
> Thanks.

Having to debug web scripts on hosts where you don't have shell access can
be a major pain. If you are referring to the wrong path in the "bang-path"
line, you'd get that error non-message. Likewise if the file permissions
were wrong.

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Re: SQLite3 and lastrowid

[Dan M]

On Tue, 16 Nov 2010 13:08:15 -0800, fuglyducky wrote:

> On Nov 16, 12:54 pm, Ian  wrote:
>> On Nov 16, 1:00 pm, fuglyducky  wrote:
>>
>> > Before I added the second table I could simply run
>> > 'print(cursor.lastrowid)' and it would give me the id number.
>> > However, with two tables I am unable to do this.
>>
>> It would help if you would show the code where you're trying to do
>> this.  Without your actual code to look at, we can't tell you why it
>> doesn't work.
>>
>> > Does anyone know if there is a way to reference one table or another
>> > to get lastrowid?
>>
>> cursor.lastrowid is always in reference to the last query executed by
>> the cursor, not in reference to a table.  If you don't capture the
>> value, and then you execute another query on the same cursor, the
>> previous value of cursor.lastrowid no longer exists.  If you need it
>> now, then either you should have captured it when you had the chance,
>> or you should not have executed another query on the same cursor.
>>
>> But perhaps this is not what you're actually trying to do.  I can't
>> tell, because I haven't seen the code.
>>
>> Cheers,
>> Ian
> 
> Thanks for the input. Sorry...I should have included the code...it's
> just a simple query...
> 
> #
> 
> import sqlite3
> import random
> 
> db_connect = sqlite3.connect('test.db') cursor = db_connect.cursor()
> 
> print(cursor.lastrowid)
> 
> # Choose random index from DB - need to understand lastrowid #row_count
> = cursor.lastrowid
> #random_row = random.randrange(0, row_count)
> 
> cursor.execute("SELECT * FROM table1 WHERE id = 2002")
> print(cursor.fetchmany())

Perhaps insert here:
cursor.execute("SELECT count() from table2")
table2lastRow = cursor.lastrowid()

> 
> #for row in cursor:
>  #   print(row)
> 
> 
> db_connect.commit()
> cursor.close()
> 
> #

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Re: [Q] get device major/minor number

[Dan M]

On Tue, 30 Nov 2010 21:09:14 +0100, Thomas Portmann wrote:

> Hello all,
> 
> In a script I would like to extract all device infos from block or
> character device. The "stat" function gives me most of the infos (mode,
> timestamp, user and group id, ...), however I did not find how to get
> the devices major and minor numbers. Of course I could do it by calling
> an external program, but is it possible to stay within python?
> 
> In the example below, I would like to get the major (8) and minor (0, 1,
> 2) numbers of /dev/sda{,1,2}. How can I get them?

I think the os.major() and os.minor() calls ought to do what you want.

>>> import os
>>> s = os.stat('/dev/sda1')
>>> os.major(s.st_rdev)
8
>>> os.minor(s.st_rdev)
1
>>> 

d...@dan:~$ ls -l /dev/sda1
brw-rw 1 root disk 8, 1 2010-11-18 05:41 /dev/sda1

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Re: [Q] get device major/minor number

[Dan M]

On Tue, 30 Nov 2010 21:35:43 +0100, Thomas Portmann wrote:

> Thank you very much Dan, this is exactly what I was looking for.
> 
> 
> Tom

You're very welcome.

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Newbie needs regex help

[Dan M]

I'm getting bogged down with backslash escaping.

I have some text files containing characters with the 8th bit set. These 
characters are encoded one of two ways: either "=hh" or "\xhh", where "h" 
represents a hex digit, and "\x" is a literal backslash followed by a 
lower-case x.

Catching the first case with a regex is simple. But when I try to write a 
regex to catch the second case, I mess up the escaping.

I took at look at http://docs.python.org/howto/regex.html, especially the 
section titled "The Backslash Plague". I started out trying :

d...@dan:~/personal/usenet$ python
Python 2.7 (r27:82500, Nov 15 2010, 12:10:23) 
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import re
>>> r = re.compile('x([0-9a-fA-F]{2})')
>>> a = "This \xef file \xef has \x20 a bunch \xa0 of \xb0 crap \xc0 
characters \xefn \xeft."
>>> m = r.search(a)
>>> m

No match.

I then followed the advice of the above-mentioned document, and expressed 
the regex as a raw string:

>>> r = re.compile(r'\\x([0-9a-fA-F]{2})')
>>> r.search(a)

Still no match.

I'm obviously missing something. I spent a fair bit of time playing with 
this over the weekend, and I got nowhere. Now it's time to ask for help. 
What am I doing wrong here?

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Re: Newbie needs regex help

[Dan M]

On Mon, 06 Dec 2010 10:29:41 -0500, Mel wrote:

> What you're missing is that string `a` doesn't actually contain four-
> character sequences like '\', 'x', 'a', 'a' .  It contains single
> characters that you encode in string literals as '\xaa' and so on.  You
> might do better with
> 
> p1 = r'([\x80-\xff])'
> r1 = re.compile (p1)
> m = r1.search (a)
> 
> I get at least an <_sre.SRE_Match object at 0xb749a6e0> when I try this.
> 
>   Mel.

That's what I had initially assumed was the case, but looking at the data 
files with a hex editor showed me that I do indeed have four-character 
sequences. That's what makes this such as interesting task!
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Re: Newbie needs regex help

[Dan M]

On Mon, 06 Dec 2010 16:34:56 +0100, Alain Ketterlin wrote:

> Dan M  writes:
> 
>> I took at look at http://docs.python.org/howto/regex.html, especially
>> the section titled "The Backslash Plague". I started out trying :
> 
>>>>> import re
>>>>> r = re.compile('x([0-9a-fA-F]{2})') a = "This \xef file \xef has
>>>>> \x20 a bunch \xa0 of \xb0 crap \xc0
> 
> The backslash trickery applies to string literals also, not only
> regexps.
> 
> Your string does not have the value you think it has. Double each
> backslash (or make your string raw) and you'll get what you expect.
> 
> -- Alain.

D'oh! I hadn't thought of that. If I read my data file in from disk, use 
the raw string version of the regex, and do the search that way I do 
indeed get the results I'm looking for.

Thanks for pointing that out. I guess I need to think a little deeper 
into what I'm doing when I escape stuff.
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Re: Newbie needs regex help

[Dan M]

On Mon, 06 Dec 2010 09:44:39 -0600, Dan M wrote:

> That's what I had initially assumed was the case, but looking at the
> data files with a hex editor showed me that I do indeed have
> four-character sequences. That's what makes this such as interesting
> task!

Sorry, I misunderstood the first time I read your reply.

You're right, the string I showed did indeed contain single-byte 
characters, not four-character sequences. The data file I work with, 
though, does contain four-character sequences.

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Re: Newbie needs regex help

[Dan M]

On Mon, 06 Dec 2010 18:12:33 +0100, Peter Otten wrote:

> By the way:
>  
 print quopri.decodestring("=E4=F6=FC").decode("iso-8859-1")
> äöü
 print r"\xe4\xf6\xfc".decode("string-escape").decode("iso-8859-1")
> äöü

Ah - better than a regex. Thanks!
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Re: Hosting a Python based TCP server

[Dan M]

On Thu, 23 Dec 2010 04:01:03 -0800, Oltmans wrote:

> Hi all,
> 
> I'm writing a very small TCP server(written in Python) and now I want to
> host it on some ISP so that it can be accessed anywhere from the
> Internet. I've never done that before so I thought I should ask for some
> advice. Do you guys know any good ISP that can let me do that?
> 
> Most importantly, what is usually involved in order to make this happen?
> 
> Please pardon my ignorance and I will really appreciate your reply.
> Thanks in advance.

Amazon Web Services is offering micro-instances (essentially a small 
virtual server) free for one year. Since you would have root access to 
the instance, you can run anything you want that doesn't violate Amazon's 
terms of service.

Send me an e-mail directly (catdude at gmail dot com) if you have 
questions about it.

Dan
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Re: Trying to decide between PHP and Python

[Dan M]

On Tue, 04 Jan 2011 12:20:42 -0800, Google Poster wrote:

> About once a year, I have to learn yet another programming language.
> Given all the recommendations (an outstanding accolade from Bruce Eckel,
> author of "Thinking in Java") I have set my aim to Python. Sounds kinda
> cool.
> 
> The indentation-as-block is unique, but that is how I always indent,
> anyway.
> 
> Can any of you nice folks post a snippet of how to perform a listing of
> the current directory and save it in a string?
> 
> Something like this:
> 
> $ setenv FILES = `ls`
> 
> Bonus: Let's say that I want to convert the names of the files to
> lowercase? As 'tolower()'
> 
> TIA,
> 
> -Ramon

1)
import os
files = ' '.join(os.listdir('/home/dan'))

2)
import os
import string
files = string.lower(' '.join(os.listdir('/home/dan')))

As to choice between Python and PHP, I would say learn anything but PHP. 
Even Perl has fewer tentacles than PHP.
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Re: Trying to decide between PHP and Python

[Dan M]

On Tue, 04 Jan 2011 12:32:28 -0800, Google Poster wrote:

> Not to mention that it took me 9 minutes to get a reply from you...
> Quite speedy community support.
> 
> That is a very important parameter in my technology decisions these
> days.
> 
> Thanks!
> 
> -Ramon

This Usenet group is a truly awesome resource. I'm a Python newbie 
myself, and the times I've posted here looking for direction I have been 
very pleased with the results.

Dan
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Re: list from FTP server to a text file

[Dan M]

On Thu, 06 Jan 2011 10:51:42 -0500, Ahmed, Shakir wrote:

> Hi,
> 
> I am trying to create a list in a txt file from an ftp server. The
> following code is retrieving the list of the files but could not able to
> write in a text file. Any help is highly appreciated.
> 
> Thanks
> 
> 
> 
> 
> import os
> import time
> from ftplib import FTP
> ftp = FTP("*.org","","")   # connect to host, default port ftp.login()
> ftp.cwd("/pub/remotefolder/")
> ftp.retrlines('NLST')
> **

WARNING: I am a newbie! Expect more pythonic ways to do this in other 
replies

from ftplib import FTP
ftp = FTP("host", "user", "pass")
ftp.cwd("/pub/myfolder")
files = ftp.nlst(".")
f = open('files.txt', 'w')
for file in files:
f.write('%s\n' % (file,))
f.close()

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Re: find in smartpdf files

[Dan M]

On Thu, 06 Jan 2011 08:11:34 -0800, Wanderer wrote:

> We generate PCB assembly files in pdf format using SmartPDF. This allows
> us to search for a component in the assembly using the find feature. We
> would like to be able to generate a list of components sorted by part
> type and then use that list to cycle through a search by ref designator
> in the pdf file. Is there a way to use Python scripts to interface PDF
> files?
> 
> Thanks

Would PDFMiner help with your task?
http://www.unixuser.org/~euske/python/pdfminer/index.html
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Newbie question - parsing MIME(?) strings

[Dan M]

I'm working on a script that grabs messages from a Usenet server and does 
some work with them. All works nicely except for a few issues with the 
data I retrieve.

For example, in one newsgroup I find occasional lines containing bits 
like:
"Re: Mlle. =?ISO-8859-1?Q?Ana=EFs_introdooses_her_ownself=2E?="

Is this some sort of bizarre MIME encoding? Looking at the data I can see 
how what the "=EF" and "=2E" mean, but that stuff after the first = has 
me confused.

And more to the point, is there a python module to handle this?
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Re: Newbie question - parsing MIME(?) strings

[Dan M]

On Thu, 28 Oct 2010 15:05:56 -0500, Dan M wrote:

Ok, I didn't research enough before I posted this. I see now that this 
*is* indeed a MIME message, and the '?Q' bit says that the next piece is 
quoted-printable, and that the encoding is defined in RFC2047.

So the question the becomes, do we have a library for reading info like
this?


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Re: python script to read google spreadsheet

[Dan M]

On Mon, 01 Nov 2010 01:14:09 -0700, charu gangal wrote:

> This is the page i am getting on localhost 8080. The code is showing me
> thr result only in Eclipse but not through google app engine launcher.
> 
> Traceback (most recent call last):
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 3211, in _HandleRequest
> self._Dispatch(dispatcher, self.rfile, outfile, env_dict)
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 3154, in _Dispatch
> base_env_dict=env_dict)
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 527, in Dispatch
> base_env_dict=base_env_dict)
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 2404, in Dispatch
> self._module_dict)
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 2314, in ExecuteCGI
> reset_modules = exec_script(handler_path, cgi_path, hook)
>   File "C:\Program Files (x86)\Google\google_appengine\google\appengine
> \tools\dev_appserver.py", line 2210, in ExecuteOrImportScript
> exec module_code in script_module.__dict__
>   File "C:\Users\Admin\Pythonworkspace\pythonsample12\src
> \engineapp202\main.py", line 4, in 
> import gdata.spreadsheet.service
> ImportError: No module named gdata.spreadsheet.service

I'm something of a Python newbie, but could Eclipse be modifying your 
PYTHONPATH by adding the directory in which gdata.spreadsheet.service is 
installed?
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Re: What people are using to access this mailing list

[Dan M]

On Wed, 03 Nov 2010 08:02:29 +, John Bond wrote:

> Hope this isn't too O/T - I was just wondering how people read/send to
> this mailing list, eg. normal email client, gmane, some other software
> or online service?
> 
> My normal inbox is getting unmanageable, and I think I need to find a
> new way of following this and other lists.
> 
> Thanks for any suggestions.
> 
> Cheers, JB.

Pan newsreader

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