Re: [Tutor] "Ctrl-C (unix)" in python
On Thu, Feb 19, 2009 at 9:44 AM, pa yo wrote: > I am running my Twitter>>Wiki bots in infinite loops but can't find > an easy way to turn them off gracefully once I have started them. At > the moment I have to go into the terminal window where they are > running and type "Ctrl-C". (I am running Ubuntu 8.10 and python 2.5.2) > > I was thinking that I could get the bot script to read a text file at > the start of the main loop and have a separate script writing the > "exit" order to the same text file but before I get too involved > with this I wanted to know if there was an built-in function to > switch scripts on and off. > > Any help or assistance much appreciated. > > Payo > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > how about kill -9 :) ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Exception Handling
On Wed, Dec 31, 2008 at 8:33 AM, David wrote:
> On Mon, 29 Dec 2008 16:57:44 +0100, spir wrote:
>>
>> > On Mon, 29 Dec 2008 09:10:45 -
>>> > "Alan Gauld" wrote:
>>> > >
>>>
>> "bob gailer" wrote
>>
> >> > Also IMHO it is bad design to put a lot of code inside a try
> block.
> >> > In this case the user might make a mistake on day and then is
> forced
> >> > to reenter the year and month!
>
>> >> Obviously there is no absolute rule here but I disagree. One of
the
>> biggest advantages of try/except error handling is that it keeps the
>> mess of handling errors out of the main logic of the code. This has
two
>> effects:
>> 1) Code that is much easier to read
>> 2) a lot less error handling code
>>> Also, I'd rather ask for the dates in one raw_input, cuts much of the
>> mess for the user (although it's a bit of extra codes)
>>
> Thank you all for the tips. Next to do is to get the dates in one raw_input
> with the correct format and to check for a valid year, month, and day. Here
> is what I have now;
> #!/usr/bin/python
> import time
>
> curr_date = time.strftime("%Y %m %d", time.gmtime())
> print "Please enter the date format as: ", curr_date
>
> while True:
>yr = raw_input("\nWhat year were you born? ")
>mn = raw_input("What month were you born? ")
>dy = raw_input("What day were you born? ")
>try:
>ynum = int(time.strftime("%Y", time.gmtime())) - int(yr)
>mnum = int(time.strftime("%m", time.gmtime()))
>dnum = int(time.strftime("%d", time.gmtime()))
>except ValueError:
>print "Oops, You must enter a number!"
>else:
>mn = int(mn)
>dy = int(dy)
>
>if mn <= mnum:
>print "You are", ynum, "years old."
>break
>elif mn == mnum and dy < dnum:
>print "You are", ynum, "years old."
>break
>else:
>ret = int(ynum) - 1
>print "You are", ret, "years old."
>break
>
>
> --
> Powered by Gentoo GNU/LINUX
> http://www.linuxcrazy.com
> pgp.mit.edu
>
> ___
> Tutor maillist - Tutor@python.org
> http://mail.python.org/mailman/listinfo/tutor
>
Hi David,
If the user enters incorrect data for the month or day, a ValueError will
still be raised
on the conversion to integer.
I suggest that you wrap your request for user information in a function that
does the checking
for you. You can re-use this function for each piece of integer information
you require from the user.
example:
import time
class BadUserError(Exception):
pass
def get_integer(retrieve, question, attempts=3):
"""
A small function to attempt to retrieve
information from a user, given a prompt question.
retrive - any function that will accept a string as an argument
and return a string or otherwise response from the user.
question - a string type question that you would like to ask the user to
respond to.
attempts[optional] - how many times the user can incorrectly
enter data before the BadUserError is raised.
"""
while attempts > 0:
num = retrieve(question)
try:
# try casting the user input as an integer.
return int(num)
except ValueError:
print "Oops, You must enter a number!"
attempts -= 1
raise BadUserError("Too many incorrect tries!")
curr_date = time.strftime("%Y %m %d", time.gmtime())
print "Please enter the date format as: ", curr_date
yr = get_integer(raw_input, "\nWhat year were you born? ")
mn = get_integer(raw_input, "What month were you born? ")
dy = get_integer(raw_input, "What day were you born? ")
today = time.gmtime()
ynum = today.tm_year - yr
mnum = today.tm_mon
dnum = today.tm_mday
if mn <= mnum:
print "You are", ynum, "years old."
elif mn == mnum and dy < dnum:
print "You are", ynum, "years old."
else:
ret = int(ynum) - 1
print "You are", ret, "years old."
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Exception Handling
On Wed, Dec 31, 2008 at 11:18 AM, David wrote: > > . I still need to get it to prduce an error if the year is 0 or 2009, the > month is 0 or 13 and the day is 0 or 32. Try using the datetime module to check validity of entered data. example: >>> import datetime >>> datetime.datetime(2008, 12, 32) # should be an error, there are only 31 days in December! ValueError: day is out of range for month > david [06:56 PM] opteron ~ $ ./py_get_age.py > Please enter the date format as: 2008 12 30 > > What year were you born? 2010 > What month were you born? 14 > What day were you born? 34 > You are -3 years old. You can also use it to check if the input is in the future. >>> userdate = datetime.datetime(2010, 1, 1) >>> datetime.datetime.now() > userdate # a check to see if userdate is in the past. False Cheers, Jervis ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Better way - fnmatch with list ? CORRECTION
On Sat, Jan 3, 2009 at 10:48 AM, bob gailer wrote: > bob gailer wrote: >> >> >> for fn in files: >> base, ext = os.path.splitext(fn) >> if ext in ['.flac','.mp3','.m4a']: ## CORRECTION removed * >> >> > for fn in files: base, ext = os.path.splitext(fn) if ext.lower() in ['.flac', '.mp3', '.mp4']: takes into account systems with case sensitive filenames. cheers, Jervis ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Question regarding win32com getting ldap object
On Mon, Jan 5, 2009 at 8:04 PM, vishwajeet singh wrote:
> Hi List,
>
> I am running following code to get ldap com object but the result I am
> getting is unknown
> I am using Python 25 and win32 bindings available at
> http://downloads.sourceforge.net/pywin32/pywin32-212.win32-py2.2.exe?modtime=1217535908&big_mirror=0
>
> *adsi = win32com.client.Dispatch('ADsNameSpaces')
> print adsi
> ldap = adsi.getobject('', 'LDAP:')
> print ldap*
>
> OutPut:
>
> >
>
> Any ideas what I am doing wrong ?
>
> --
> Cheers,
> Vishwajeet
> http://www.singhvishwajeet.com
>
> ___
> Tutor maillist - Tutor@python.org
> http://mail.python.org/mailman/listinfo/tutor
>
> Hi,
try the following from the archive:
http://mail.python.org/pipermail/python-list/1999-December/018594.html
Cheers,
Jervis
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Gamma distribution function
On Wed, Jan 14, 2009 at 8:27 AM, culpritNr1 wrote: > > > there some kind of random.poisson()? > > Thank you, > > culpritNr1 > > Hello try the scipy library: >>> from scipy import stats >>> lamb = 10 >>> stats.distributions.poisson.rvs(lamb, loc=0) array([5]) >>> stats.distributions.poisson.rvs(lamb, loc=0) array([14]) http://www.scipy.org/ cheers, ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Fwd: Gamma distribution function
-- Forwarded message --
From: Jervis Whitley
Date: Wed, Jan 14, 2009 at 9:26 AM
Subject: Re: [Tutor] Gamma distribution function
To: culpritNr1
On Wed, Jan 14, 2009 at 9:11 AM, culpritNr1 wrote:
>
> The python documentation on this functionality is extremely poor. Look
> >>> help("scipy.stats.distributions.poisson.rvs")
> Help on method rvs in scipy.stats.distributions.poisson:
> scipy.stats.distributions.poisson.rvs = rvs(self, *args, **kwds) method of
> scipy.stats.distributions.poisson_gen instance
>
> Do you understand what's going on?
>
> Thanks,
>
> culpritNr1
>
>
> --
> View this message in context:
> http://www.nabble.com/Gamma-distribution-function-tp21444899p21445597.html
> Sent from the Python - tutor mailing list archive at Nabble.com.
>
> ___
> Tutor maillist - Tutor@python.org
> http://mail.python.org/mailman/listinfo/tutor
>
Your previous email said you wanted to sample from the poisson function,
which is what that rvs method is doing, taking random samples from a poisson
distribution of lambda = 1 in your case. They also provide a means to shift
the function from a nominal x crossing of 0 using the second argument, in
your case you have used 2. So you were sampling from a function of mean 1
shifted right by 2.
The below has been taken from the poisson documentation itself:
print stats.distributions.poisson.__doc__
A poisson discrete random variable.
Discrete random variables are defined from a standard form.
The standard form may require some other parameters to complete
its specification. The distribution methods also take an optional
location
parameter using loc= keyword. The default is loc=0. The calling form
of the methods follow:
poisson.rvs(mu,loc=0)
- random variates
poisson.pmf(x,mu,loc=0)
- probability mass function
poisson.cdf(x,mu,loc=0)
- cumulative density function
poisson.sf(x,mu,loc=0)
- survival function (1-cdf --- sometimes more accurate)
poisson.ppf(q,mu,loc=0)
- percent point function (inverse of cdf --- percentiles)
poisson.isf(q,mu,loc=0)
- inverse survival function (inverse of sf)
poisson.stats(mu,loc=0,moments='mv')
- mean('m',axis=0), variance('v'), skew('s'), and/or kurtosis('k')
poisson.entropy(mu,loc=0)
- entropy of the RV
Alternatively, the object may be called (as a function) to fix
the shape and location parameters returning a
"frozen" discrete RV object:
myrv = poisson(mu,loc=0)
- frozen RV object with the same methods but holding the
given shape and location fixed.
You can construct an aribtrary discrete rv where P{X=xk} = pk
by passing to the rv_discrete initialization method (through the values=
keyword) a tuple of sequences (xk,pk) which describes only those values
of
X (xk) that occur with nonzero probability (pk).
Poisson distribution
poisson.pmf(k, mu) = exp(-mu) * mu**k / k!
for k >= 0
If you are after a probability at a given k (which it now sounds like you
may be after) you might be interested in the
pmf method.
(Sorry I did a reply instead of reply-all)
Cheers,
Jervis
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] eval and floating point
On Thu, Jan 15, 2009 at 1:19 PM, Mr Gerard Kelly wrote:
> Thanks very much
>
> I've noticed that the eval() function gives an integer, so eval("3/2")
> gives back 1. float(eval("3/2")) doesn't seem to work, any way to get a
> floating point number back with eval()?
>
> I know you can just do ("3./2."), but is there any way to do it with
> just ("3/2")?
> ___
> Tutor maillist - Tutor@python.org
> http://mail.python.org/mailman/listinfo/tutor
>
Hi,
at the top of your script you can write:
from __future__ import division
now
>>> eval("4/3")
1.3
You can read up on it here if you are interested..
http://www.python.org/dev/peps/pep-0238/
Cheers
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] single key ordered sequence
On Fri, Jan 16, 2009 at 4:56 AM, Senthil Kumaran wrote: > > Also, how to practically walk in reverse order in a list without > > copying it (e.g. items[::-1]), > > especially if i need both indexes and items (couldn't find with > > enumerate()). > > > Are you looking for reversed()? > The way you are doing it is probably OK. > But it can be simplified thus: > > keys = [] > target = [] > > for item in reversed(items): > if not item[0] in keys: >keys.append(item[0]) >target.append(item) > > print target > > If this is not what you wanted,then I have misunderstood your > requirement and just based it on your code. > > Thanks, > Senthil > ___ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor > how about this: items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'), (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')] mydict = dict(items) items = [item for item in mydict.iteritems()] testing shows: C:\WINDOWS\system32\cmd.exe /c python test_time.py **ORIGINAL** s = """ items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'), (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')] keys = [] for index in range(len(items)-1,-1,-1): key = items[index][0] if key in keys: items[index] = None else: keys.append(key) items = [item for item in items if item is not None] """ timeit.Timer(stmt=s).timit() 5.40928835422 **Test1** s = """ items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'), (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')] keys = [] for item in reversed(items): key = item[0] if key in keys: items.remove(item) else: keys.append(key) #items = [item for item in items if item is not None] """ timeit.Timer(stmt=s).timit() 5.02896436267 **Test2** s= """ items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'), (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')] keys = dict(items) items = [item for item in keys.iteritems()] """ timeit.Timer(stmt=s).timit() 3.38715506199 Hit any key to close this window... ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] single key ordered sequence
On Fri, Jan 16, 2009 at 9:15 AM, Kent Johnson wrote: > On Thu, Jan 15, 2009 at 3:44 PM, Jervis Whitley > wrote: > > how about this: > > items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'), > > (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')] > > mydict = dict(items) > > items = [item for item in mydict.iteritems()] > > That only coincidentally preserves order; the order of items in a > dictionary is, for practical purposes, unpredictable. > > BTW [item for item in mydict.iteritems()] can be written as just > mydict.items(). > > Kent I realise that what you have said is true, however can you show me a case where > items = dict(items).items() will not preserve order? Thanks. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] single key ordered sequence
On Fri, Jan 16, 2009 at 10:39 AM, bob gailer wrote:
> Jervis Whitley wrote:
>
>>
>>
>> On Fri, Jan 16, 2009 at 9:15 AM, Kent Johnson > ken...@tds.net>> wrote:
>>
>>On Thu, Jan 15, 2009 at 3:44 PM, Jervis Whitley
>>mailto:jervi...@gmail.com>> wrote:
>>> how about this:
>>> items = [(1,'a'),(1,'b'),(2,'a'),(3,'a'),
>>> (3,'b'),(4,'a'),(5,'a'),(5,'b'),(5,'c')]
>>> mydict = dict(items)
>>> items = [item for item in mydict.iteritems()]
>>
>>That only coincidentally preserves order; the order of items in a
>>dictionary is, for practical purposes, unpredictable.
>>
>>BTW [item for item in mydict.iteritems()] can be written as just
>>mydict.items().
>>
>>Kent
>>
>> I realise that what you have said is true, however can you show me a case
>> where
>> > items = dict(items).items()
>>
>> will not preserve order? Thanks.
>>
>>
> On my computer:
>
> >>> dict((('z', 1), ('y', 2))).items()
> [('y', 2), ('z', 1)]
>
> --
> Bob Gailer
> Chapel Hill NC
> 919-636-4239
>
Same on mine, thanks.
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] running & debugging in python interactive she
On Fri, Jan 16, 2009 at 9:56 AM, Che M wrote: > > > > >> I'd like to add to this question and expand it: can anyone point me to > >> a good resource on debugging *generally*? > > The first result on "Debugger tutorial" on google sent me to this: > > > http://www.cs.princeton.edu/~benjasik/gdb/gdbtut.html > > > Though it's for a specific program, it seems to have some good general > purpose advice. > > Personally, I've never had the need for a debugger (maybe because I'm not > writing complicated > > enough programs) - a simple "print" statement (in the right spot) tends > to take care of all of my > > debugging needs. > > That page didn't strike me as very helpful for my case, but thanks > anyway. I'll Google for it, too, but just wondered if any of the > tutors here had any recommendations. I just checked Alan Gauld's > tutorial and I see it doesn't have a debugger section (completely > understandably, as this is sort of advanced). > > I also use print statements a fair bit. I've just heard that using > a debugger is a very useful thing and I thought maybe someone would > have some tips here or knew of a good Python-relevant tutorial about it. > > Thanks, > Che > > > -Wayne > > I did a search for 'python pdb tutorial' and found this resource: http://www.ferg.org/papers/debugging_in_python.html pdb is the python debugger, this tutorial will give you more than enough to get started. Cheers, ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Properties of an object
> > > > For me, the "()" look like artificial, not necessary. I would prefer just > to type"a.list_1stpart" , a property. > > > > -- > > Others have explained their preference for using get methods for accessing internal data structures, However it does look like you have specifically mentioned a preference for attribute like access: e = ExampleList([1,2,3,4], 2) >>> e.firstpart [1,2] rather than >>> e.firstpart() [1,2] We can implement this using properties, and I will refer you to some of the documentation http://docs.python.org/library/functions.html#property Here is just one way that you could simply implement a property in your case: class ExampleList(object): """Note that this is a new style class.""" def __init__(self, sequence, position): self._sequence = sequence self._position = position @property def firstpart(self): """This method will be called on inst.firstpart rather than inst.firstpart().""" return self._sequence[:self._position] Here I have used property as a decorator (described in the link), now you can get your firstpart through attribute access (not that you cannot 'set' to it): e.firstpart Cheers, ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] regex: not start with FOO
On Tue, Feb 3, 2009 at 9:46 AM, Bernard Rankin wrote:
> Hello,
>
>
> I'd like to match any line that does not start with FOO. (Using just a
> reg-ex rule)
>
> 1) What is the effective difference between:
>
> (?!^FOO).*
>
> ^(?!FOO).*
>
> 2) Is there a better way to do this?
>
myline = 'FOO things in line'
>>> myline.startswith('FOO')
True
Cheers,
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
