🌐 Mailman 3 February 2003 - Tutor - python.org

Backslashes inside of variable
by Phoebus Nov. 24, 2003

Nov. 24, 2003

I am running Python 2.2 on Win2k. I have a program which writes a filename, with backslashes to a file, along with other stuff. I read the file in using readlines() and put each line into a variable. My problem is I want to use the filename, but I can't use it because of the backslashes. I know about doing open(r"d:\test\file.txt","w") or even open(`d:\test\file.txt`,"w"), but the filename is inside of a variable so when I do open(filename,'w'), I have problems. Can anyone help? Thanks, Steve --

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[Baypiggies] ANN: BayPIGgies mtg Wed 11/13 7:30pm (fwd)
by Wesley Chun April 4, 2003

April 4, 2003

BayPIGgies: Silicon Valley-San Francisco Bay Area Python Users Group When: December 11, 2002 @ 7:30pm Where: Stanford University, Palo Alto, CA Agenda: Newbies' Nite Speaker: (everyone!) Due to popular demand, we are having another Newbie Night (e.g. April 2002). This is the chance for all Python programmers to bring their friends and colleagues who should hear about Python. It is also for those who want to or are picking up Python and have questions! We will have a good number of Python experts who will try and help you out. Perl and Java experts are welcome too, as many Python developers also have experience there and can give you an honest comparison. The format is this: Wesley (or Danny) will give just a short half-hour intro presentation on Python to beginners followed by a quick demo, and then we will open it up to everyone for Q&A. Mingling and networking will bring our meeting to a glorious conclusion. :-) # NOTE: the next meeting on January 8, 2003 will be not be at the usual # place... stay tuned for a location update. # Call For Talks: We are actively seeking speakers for BayPIGgies! If you would like to give a talk at one of our 2003 meetings (any Python related topic), contact us to coordinate! more info including directions: http://www.baypiggies.net hope to see some of you next Wednesday! -wesley - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - "Core Python Programming", Prentice Hall PTR, � 2001 http://starship.python.net/crew/wesc/cpp/ Silicon Valley-San Francisco Bay Area Python Users Group (BayPIGgies) http://deirdre.org/baypiggies wesley.j.chun :: wesc at deirdre.org cyberweb.consulting : henderson, nv : cyberweb at rocketmail.com http://www.roadkill.com/~wesc/cyberweb/

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script still too slow
by Paul Tremblay March 1, 2003

March 1, 2003

After re-writing parts of my script for 8 hours yesterday, it is still almost 3 times slower than its perl counterpart. The script reads in an RTF file and then breaks it into tokens. It then makes several passes through the file, reading each token and performing the appropriate action. I have profiled the script using Python's profile utility. There is no one function that slows down the script. Rather, each function seems to take as much time. Here is an example: def evaluate_token(self,token): """Evaluate tokens. Return a value if the token is not a control word. Otherwise, pass token onto another method for further evaluation.""" if token == '{': self.__bracket_count = self.__bracket_count + 1 num = '%04d' % self.__bracket_count token = 'ob<nu<nu<nu<%(num)s<{\n' % vars() elif token == '}': num = '%04d' % self.__bracket_count token = 'cb<nu<nu<nu<%(num)s<}\n' % vars() self.__bracket_count = self.__bracket_count - 1 elif token == r'\{': token = 'tx<es<nu<nu<nu<{\n' elif token == r'\}': token = 'tx<es<nu<nu<nu<}\n' elif token == r'\\': # double or escaped \ token = 'tx<es<nu<nu<nu<\\\n' elif token[0:1] != '\\': # single \ token = 'tx<nu<nu<nu<nu<%(token)s\n' % vars() else: token = self.evaluate_cw(token) return token This function takes around 17 seconds to run. The tokens have to be further evaluated in many cases with two other functions. Each of these functions takes 17 seconds as well. So far, I have only conerted the first two parts of the script from python to perl. So far, these first two steps take 3 times as long as perl. At this rate, the script could take over 6 minutes to process a file. That is much too long. I am beginning to think that python is just much slower than perl, and shouldn't be used for this task? Sorry I am vague on asking specifics, but I can't really pin point the exact problem with speed, and obviously I can't dump hundreds of lines on the mailing list. Thanks Paul -- ************************ *Paul Tremblay * *phthenry(a)earthlink.net* ************************

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Object Instantiation via Dictionary Values
by Sean Abrahams Feb. 28, 2003

Feb. 28, 2003

I want to create new objects with names and classes that are stored inside a list of dictionaries. Example: modules = [{'Name' : 'Sean', 'Type' : 'Person'}, {'Name' : 'Buddy', 'Type' : 'Dog'}, {'Name' : 'Evil', ' Type' : 'Cat'}] for module in modules: module['Name'] = module['Type'].module['Type']() # Would be: # Sean = Person.Person() # Buddy = Dog.Dog() # Evil = Cat.Cat() I'm not exactly sure how to go about this, but assume it has something to do with using special methods. Thanks, --Sean

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Re: [Tutor] Attribute.Error: 'list' object has no attribute strip
by vicki＠stanfield.net Feb. 28, 2003

Feb. 28, 2003

Thanks. I only needed to do part of what you suggested. The line: string=(Pmw.ScrolledListBox.getcurselection(self))[0] gave me the 09 that I was looking for. Thanks for your patience. --vicki

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raw_input and converting string to digit
by Mic Forster Feb. 28, 2003

Feb. 28, 2003

Hi Guys, The purpose of this script is to obtain an expected species-abundance curve given an observed curve. The script works fine for this purpose but it is cumbersome to implement. What I am trying to do is to open this file, enter in a number that represents the fundamental biodiversity number (theta) and another that represents the community size (jM), let the program do its stuff and then give the expected abundance output. I am unsure of the correct syntax to convert a string from raw_input into a digit. Here is what I have (any additional comments on any aspect of this code is more than welcome): >>>from random import random as rnd >>>theta = [] >>>def addTheta(): theta.append(raw_input(�Fundamental biodiversity number is: �)) >>>jM = [] >>>def addJM: jM.append(raw_input(�The metacommmunity size is: �)) >>>class growList(list): '''A list that does as in Perl: Grows when we assign to new indices. I.e. x[1] = 5 will work if x was previously empty.''' def __setitem__(self, i, val): while i >= len(self): self.append(None) list.__setitem__(self, i, val) def __getitem__(self, i): 'Return 0 for unused slots' if i < len(self): return list.__getitem__(self, i) else: return 0 >>>abund = growList() >>>abund[1] = 1 >>>cumul = growList() >>>def nsp(): '''Number of species must be the same as the size of the abundence list (I guess). Note that first position is unused to match the 1-based algorithm syntax.''' return len(abund) - 1 >>>for j in range(2, jM + 1): x = rnd() if x < (theta / float(theta + j - 1)): abund.append(1) else: cumul[1] = abund[1] / float(j-1) for i in range(2, nsp()+1): cumul[i] = cumul[i-1] + abund[i] / float(j-1) i = 1 while x >= cumul[i]: i += 1 abund[i] += 1 >>>for abundance in zip(abund): print '%s' % abundance __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/

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Attribute.Error: 'list' object has no attribute strip
by vicki＠stanfield.net Feb. 28, 2003

Feb. 28, 2003

Thanks for all the help with the listbox callback stuff. Now onto something else. I am trying to use the strip function on the data which is returned from a getcurselection() call on that same listbox. What is returned is in the following format (number will vary): ('06',) I want to get only the number part, so I use the following: command=string.strip([(),]) The error I get is Attribute.Error: 'list' object has no attribute strip I am including the string module. Can anyone tell me what I am missing (this time)? --vicki

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Attribute.Error: 'list' object has no attribute strip
by vicki＠stanfield.net Feb. 28, 2003

Feb. 28, 2003

Thanks for all the help with the listbox callback stuff. Now onto something else. I am trying to use the strip function on the data which is returned from a getcurselection() call on that same listbox. What is returned is in the following format (number will vary): ('06',) I want to get only the number part, so I use the following: command=string.strip([(),]) The error I get is Attribute.Error: 'list' object has no attribute strip I am including the string module. Can anyone tell me what I am missing (this time)? --vicki

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passing widget to callback before defined
by vicki＠stanfield.net Feb. 28, 2003

Feb. 28, 2003

What do you do when you have to define the callback when the item is created (ScrolledListBox has the selectioncommand argument) and you want to pass the name of the item to the callback. As shown below, the selectioncommand needs to use the name Listbox1 before the Listbox is actually defined. ---------------------------------- callback=SimpleCallback(CommandCallback,Listbox1) Listbox1=Pmw.ScrolledListBox(Frame3, selectioncommand=callback, listbox_height=1, labelpos='w', label_text='Commands', items=("06", "09")) Listbox1.pack() --------------------------------- For the record, the callback looks something like this: ---------------------------------- def CommandCallback(Listbox1) index=Pmw.ScrolledListBox.getcurselection(self.Listbox1) --------------------------------- Regards, --vicki

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re: Script too slow
by Charlie Clark Feb. 28, 2003

Feb. 28, 2003

On 2003-02-27 at 18:00:07 [+0100], tutor-request(a)python.org wrote: > I have profiled the script using Python's profile utility. There is no > one function that slows down the script. Rather, each function seems to > take as much time. Here is an example: > > > def evaluate_token(self,token): > """Evaluate tokens. Return a value if the token is not a control > word. Otherwise, pass token onto another method for further > evaluation.""" > if token == '{': > self.__bracket_count = self.__bracket_count + 1 > num = '%04d' % self.__bracket_count > token = 'ob<nu<nu<nu<%(num)s<{\n' % vars() > elif token == '}': > num = '%04d' % self.__bracket_count > token = 'cb<nu<nu<nu<%(num)s<}\n' % vars() > self.__bracket_count = self.__bracket_count - 1 > elif token == r'\{': > token = 'tx<es<nu<nu<nu<{\n' > elif token == r'\}': > token = 'tx<es<nu<nu<nu<}\n' > elif token == r'\\': # double or escaped \ > token = 'tx<es<nu<nu<nu<\\\n' > elif token[0:1] != '\\': # single \ > token = 'tx<nu<nu<nu<nu<%(token)s\n' % vars() > else: > token = self.evaluate_cw(token) Paul, I'm probably the last person who can really help you on this but there are a couple of things that strike me about this function. First of all you can use self_bracket += 1 to get a bit more speed!!! Not much and I can't really tell you why but it is faster, it has something to do with only one value being used... I don't know how you're getting your tokens but it looks this looks a lot like the stuff you write when using the HTML/SGML-parser. Are you hooked up to an RTF-Parser to do all the stuff? If not it might be worth looking at the SGMLParser code as to how it deals with <tag/> stuff - looks quite analogue to your "{", "}" stuff. Python has a nioe way of avoiding long if, elif, ... else. You can use dictionaries. ie. d_test 0 = {"{":count+1, "}":count-1, r"\{":"tx"} try: fn(d_test[token]) # some function which knows what to or use exec except KeyError: other_fn(token) that might be a little tricky to get right but should run faster, particularly for longer comparisons it's only one look-up per token. Hope this is a little helpful. Charlie

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