Hey Mark Id be very much interested in this. While I mostly lurk on the python mailing list and have only dabbled in a few quick scripts. Then I wouldnt mind getting deeper into via a collective group.
This is the first I've heard of this, Im not sure if you've posted before but which book are you using? /Regards Tommy On Tue, 29 Nov 2011 10:18:25 +0100, tutor-requ...@python.org wrote: > Send Tutor mailing list submissions to > tutor@python.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://mail.python.org/mailman/listinfo/tutor > or, via email, send a message with subject or body 'help' to > tutor-requ...@python.org > > You can reach the person managing the list at > tutor-ow...@python.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Tutor digest..." > > > Today's Topics: > > 1. Re: How to handle try and except in this case (Mic) > 2. Re: useful function or reinventing the wheel?? (Mark Lybrand) > 3. Programming Collective Intelligence Study Group (Mark Lybrand) > 4. Re: Do loop in Python (stm atoc) > 5. Re: How to handle try and except in this case (Dave Angel) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 29 Nov 2011 09:37:28 +0100 > From: "Mic" <o0m...@hotmail.se> > To: <tutor@python.org> > Subject: Re: [Tutor] How to handle try and except in this case > Message-ID: <col124-ds7ac3d458b3f5fa994a929b7...@phx.gbl> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > > On 2011-11-27 17:58, Mic wrote: >>> Say that I want to try and open 10 files. If none of these exists, I >>> want >>> an >>> error >>> message to appear. But only if NONE of these files exists. > >>> I know how to handle this with one file. But I don't know how to do that >>> with more than one. >>> So the program should try and open all 10 files and if, and only if, >>> none >>> of the files exists I want en error message to appear. > > > [Andreas wrote]: >>Use a counter which increments with every existing file. After opening >>all files check if the counter is bigger than 0. > >>Or, if you need to know which files exist, use a list, append existing >>files to it and check at the end if it's not empty. > >>Do you need more help? > > Andreas, > > > Thanks for your answer. I am afraid I don't understand this: > "Use a counter which increments with every existing file. After opening > all files check if the counter is bigger than 0." > > > I thought I could co along those lines earlier > > try: > text_file=open("Hey","r") and text_file1=open("Hey","r") > except: > print("hi") > > > So that hi is printed only and only if both files aren't existing. > > > Thank you! > > > > > > > > ------------------------------ > > Message: 2 > Date: Tue, 29 Nov 2011 00:37:40 -0800 > From: Mark Lybrand <mlybr...@gmail.com> > To: d...@davea.name > Cc: tutor@python.org > Subject: Re: [Tutor] useful function or reinventing the wheel?? > Message-ID: > <CALsUBtzEvCyynA=PPip3OVDM=bw5h3w3pcur0dctprbg--2...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > >> >> >> You're welcome. I'd look forward to seeing your rewrite, and whether >> it's >> really shorter and more straightforward. >> >> Another advantage is doing less disk I/O if you start by trying the >> requested directory directly, and only recursing to parents if you can't >> make the requested directory. >> >> I took a quick stab at it (ask me later for mark.py) and it wasn't as >> straightforward as I expected. The main problem comes down to how to >> define the base case. I think you might have the same problem also. You >> assume that you can safely go back to the mount point. But if the path >> given is relative, you have to allow for that as well. Perhaps a call to >> os.path.abspath is in order. I also think that ismount() might not be >> legal on Windows, if you care about that. >> >> Also, we have to worry about what happens when one of the directories >> cannot be made for reasons unrelated to the syntax of the string. For >> example, the user might not have write permissions for one or more of the >> directories. In fact, the user might not have read permissions either. >> >> > I am actually passing in the path already os.path.abspath-ed. So, I should > probably move that into the function for better encapsulation. I am on > Windows, so ismount is behaving correctly (I tested it in Idle before going > with that as my base case). Since this will end up being a throw-away, I > will probably not worry too much about permissions and failures, but I can > appreciate the need for such checks, should I decide to keep this for more > widespread use. > > Thanks again. I will send my solution when I get a chance to get back to > it (gotta get myself ahead in machine learning before the weekend gets too > close :) > > Mark > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://mail.python.org/pipermail/tutor/attachments/20111129/991cc3a9/attachment-0001.html> > > ------------------------------ > > Message: 3 > Date: Tue, 29 Nov 2011 00:42:01 -0800 > From: Mark Lybrand <mlybr...@gmail.com> > To: tutor@python.org > Subject: [Tutor] Programming Collective Intelligence Study Group > Message-ID: > <calsubtzsqtjh4mx2ixuvo-j5ztn5xqlt+o4zdyevse1vjkn...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Over on the Machine Learning Class, I mentioned the idea of setting up some > online resources to go through the Programming Collective Intelligence book > as a group. This would include a group or discussion board of some type, > maybe a Google+ or Facebook page, and a wiki. Then we would set a pace and > work through the book. Since it is in Python, I thought this group would > be interested. Am I wrong? If it works out pretty good, we will probably > continue with Natural Language Processing (also Python) after we finish. > > So, what is the interest like here? Let me know and I will give you guys a > heads up when I get everything all set up. > > -- > Mark :) > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://mail.python.org/pipermail/tutor/attachments/20111129/82dcebaf/attachment-0001.html> > > ------------------------------ > > Message: 4 > Date: Tue, 29 Nov 2011 09:51:45 +0100 > From: stm atoc <stm.at...@googlemail.com> > To: Andreas Perstinger <andreas.perstin...@gmx.net> > Cc: tutor@python.org > Subject: Re: [Tutor] Do loop in Python > Message-ID: > <cahnhts68pqeq5xvk4tn3c6hqymenrby1o7xnqn-fxjmdki4...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Thank you so much. This script and all information was totally helpful > and actually helped me for the next step of my work as well. > > Have a great time..... > Sue > > On Fri, Nov 25, 2011 at 10:44 PM, Andreas Perstinger > <andreas.perstin...@gmx.net> wrote: >> On 2011-11-25 14:46, stm atoc wrote: >>> >>> Here is the new version of the program: >>> >>> zvalues = [-200] ?# starting value >>> hvalues = [10] ?# starting value >>> increments = [1, 1, 1, 1, 1, 1, 1, 1] >>> for N in increments: >>> ? ? ? ?h = hvalues[-1] - N >>> ? ? ? ?hvalues.append(h) >>> ? ? ? ?z = zvalues[-1] + h >>> ? ? ? ?zvalues.append(z) >>> ? ? ? ?height = arange((z)*dz,0,dz) >> >> >> There is no "arange" in python. Could it be that you use numpy and >> import it >> with "from numpy import *"? >> >>> ? ? ? ?for z,when in enumerate(height): >> >> >> I'm pretty sure this line doesn't do what you expect it to do. You have a >> sequence (a numpy array) named "height" and after calling "enumerate" you >> get a list of tuples in the form of [(0, height[0]), (1, height[1]), >> ...]. >> Now the for-loop iterates over this list and assigns "z" to the first >> value >> of the tuple (the index-values) and "when" to the second (the values from >> "height"). You later never use "when" but just use "z". If you really >> want >> that, the "enumerate" is completly unnecessary and you could just use >> "for z >> in range(len(height))". But I'm not sure if numpy arrays work with >> "len()". >> >> >>> ? ? ? ? ? ?nuh.append(0.001 * exp(-0.005*(z+200.0))*dz) #turbulence >>> diffusivity m**2/s >>> ? ? ? ? ? ?nu.append(num + nuh[z]) >>> >>> The story is like this: >>> I should define layers and thickness and see how the diffusion profile >>> changes over the z. >>> height (or depth) of the total thickness or 'z'. >>> I basically, define 'z' in 10 layers and each layer is called ?' N' . >>> Difference between each layer is 'h', which is equal 10 micrometer. >>> Now, what I like to do is the modification of nu based on each zvalue >>> In fact, for each 'zvalue' o'z' step, I need to calculate a different >>> value for 'nu' based on the available equation in the program. >>> >>> BUT, I am not sure, exactly, how to add the new do loop of z inside >>> another loop of nu. >> >> >> For me your explanations are still too confusing. Could it be that you >> are >> thinking way too complicated? >> >> My guess is you want to have a range of material thicknesses (from 1 to >> 200 >> micrometers in 10 micrometer-steps) and then you want from each >> thickness 10 >> different layers, right? >> >> import math # you should always tell us which modules you import >> num = 0.05 # some constant >> nu = [] # list of resulting values >> h = 10.0 # height of one layer >> thickness = range(0, 210, 10) # a list from 0 to 200 with step 10 (0, 10, >> 20, ..., 190, 200) >> layers = range(1,11) # a list from 1 to 10 >> for t in thickness: >> ?for l in layers: >> ? ?z = t + h * l # I'm not sure if you want to add or subtract the layer >> thickness >> ? ?nu = num + (0.01 * math.exp(-0.05 * (z + 200.0))) >> >> This will result in a big one-dimensional list where you calculate for >> each >> thickness the nu-value for 10 layers. Am I close? >> I'm still not sure about the steps and the height of the layers. I also >> wonder if it wouldn't be better to use a two-dimensional list. >> >> >>> I have done this way as well (the other way around): >>> >>> height = arange((z)*dz,0,dz) >>> for z,when in enumerate(height): >>> ? ? for N in increments: >>> ? ? ? ?h = hvalues[-1] - N >>> ? ? ? ?hvalues.append(h) >>> ? ? ? ?z = zvalues[-1] + h >>> ? ? ? ?zvalues.append(z) >>> ? ? ? ?nuh.append(0.001 * exp(-0.005*(z+200.0))*dz) #turbulence >>> diffusivity m**2/s >>> ? ? ? ?nu.append(num + nuh[z]) >>> >>> but still no sign of 'nu changes' over 'z'! >> >> >> As Charles has already mentioned, the values for "nu" are very similar >> (they >> start beginning to differ just at the seventh digit after the comma). >> How do >> you further process this values? If you plot them what's your scale? >> >> Bye, Andreas >> >> _______________________________________________ >> Tutor maillist ?- ?Tutor@python.org >> To unsubscribe or change subscription options: >> http://mail.python.org/mailman/listinfo/tutor > > > ------------------------------ > > Message: 5 > Date: Tue, 29 Nov 2011 04:17:55 -0500 > From: Dave Angel <d...@davea.name> > To: Mic <o0m...@hotmail.se> > Cc: tutor@python.org > Subject: Re: [Tutor] How to handle try and except in this case > Message-ID: <4ed4a343.1020...@davea.name> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 11/29/2011 03:37 AM, Mic wrote: >> >> On 2011-11-27 17:58, Mic wrote: >>>> Say that I want to try and open 10 files. If none of these exists, I >>>> want an >>>> error >>>> message to appear. But only if NONE of these files exists. >> >>>> I know how to handle this with one file. But I don't know how to do >>>> that >>>> with more than one. >>>> So the program should try and open all 10 files and if, and only if, >>>> none >>>> of the files exists I want en error message to appear. >> >> >> [Andreas wrote]: >>> Use a counter which increments with every existing file. After opening >>> all files check if the counter is bigger than 0. >> >>> Or, if you need to know which files exist, use a list, append existing >>> files to it and check at the end if it's not empty. >> >>> Do you need more help? >> >> Andreas, >> >> >> Thanks for your answer. I am afraid I don't understand this: >> "Use a counter which increments with every existing file. After opening >> all files check if the counter is bigger than 0." >> > Could you explain what's unclear about it? Andreas couldn't get more > specific, since you didn't say how these 10 names are provided. If > they're in a list called filenames, you could do something like: > > fileobjects = [] > for fname in filenames: > try: > fileobj = open(fname, "r") > fileobjects.append(fileobj) > catch SomeExceptionType as e: > pass > > and when you're done, use something like: > > if len(fileobjects) == 0: > print "no files could be opened" > >> >> I thought I could co along those lines earlier >> >> try: >> text_file=open("Hey","r") and text_file1=open("Hey","r") > > Unfortunately this isn't valid Python syntax. The equal sign has a > specific statement syntax, and the only time you can have more than one > of them in one statement, is the chained assignments, where they all get > bound to the same object. You wouldn't want to do this anyway, since it > would leave all those open files in an unspecified state. > > To go one step further, if it could work, it would give an exception if > any ONE of the files couldn't be open, and you want the message to > appear if none of the files could be opened. > >> except: >> print("hi") >> >> >> So that hi is printed only and only if both files aren't existing. > If you didn't need to open them, but just to make sure they exist, you > could use if os.exist(filename) much more easily. _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
