🌐 Mailman 3 November 2014 - Tutor - python.org

Scripting Calligra sheets with Python
by Jim Byrnes Jan. 31, 2022

Jan. 31, 2022

I am trying to script Calligra Sheets (formerly KSpread) with python. I have gotten some of the included example scripts to run so I know python scripting is running. I found the following snippet on their website: import KSpread sheet = KSpread.view().sheet() # swap text of B5 and C6 t1 = sheet.text("B5") t2 = sheet.text(6,3) sheet.setText("B5", t2) sheet.setText(6, 3, t1) # swap value of D7 and E8 v1 = sheet.value("D7") v2 = sheet.value(8,5) sheet.setValue("D7", v2) sheet.setValue(8, 5, v1) Error: 'str' object has no attribute 'text' File "file:///usr/share/kde4/apps/sheets/scripts/extensions/myswap.py", line 4, in <module> This error message appeared in a dialog box. I've taught myself some Python but I don't understand what is happening here. Shouldn't t1 be a sheet object? What would cause it to be a str instead? Thanks, Jim

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Desktop Notifications on Linux
by Dharmit Shah June 29, 2017

June 29, 2017

Hi all, I am trying to create a script that will go through the /var/log/secure file on a Linux system and provide desktop notifications for failed login attempts. Here is the code - http://pastebin.com/MXP8Yd91 And here's notification.py - http://pastebin.com/BhsSTP6H I am facing issue in the function "new_attempts_from_last". I am not able to raise a desktop notification from this function. It always fails with this traceback - http://pastebin.com/cgHMScv3 I see this error only when I try to raise a notification from the aforementioned function. If I run test examples under /usr/share/doc/notify-python/examples, it works just fine. Also, if I try to raise a notification from under if __name__ == "__main__":, it works without any issues. So I don't think there's any issue with OS's notification daemon. Running from python shell like below also works fine: In [1]: import notification In [2]: notification.notification("Hey") What am I missing or doing wrong here? If it matters, I am running Fedora 20, python 2.7 and Cinnamon desktop environment. For readability purposes, I have provided pastebin links. Let me know if this is not the correct way. Regards, Dharmit.

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Option on How to create web Interface
by fabu desay March 9, 2016

March 9, 2016

If I got the problem correctly,you can equally create + open a file file = open(filename,+wr) The file should have the HTML extension You can now pace your web contents in the file.html you created that should work by trigering the python file you programed in and it inturn creates the website or pages of your choice an example like this could help webpage = open('index.html', 'w+') webpage.write("<html><head><title>My web page</title></head>"); webpage.write("<body>This the body</body></html>"); webpage.close()

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HELP I need help with Python Setup or to reach Marilyn Davis
by carolynn fryer July 12, 2015

July 12, 2015

I am at the point where I am just spinning my wheels. I tried to get help with logging on but so far I am just getting frustrated. I have a problem that I brought up the first night in class but couldn't seem to get help then. Sorry if I am at the point where I am totally frustrated and I need HELP. PLEASE. I did not turn in homework because of the fact that I can not run anything without getting a syntax error. I tried setting up a path for python environment variables and a few other things but I am getting no where. Can you give me some suggestions why I can't run anything. I have windows 7 on my home computer, and windows 8 on my laptop and they are both doing the same thing. So it has to be something I am doing or not doing. I really do not like being behind/late in anything so that is making me even more frustrated. I suppose I am even more frustrated and afraid to ask because I kink of got a slap in the face last time I took a course here and the instructor would not help. But that was a way different situation, I simply could not understand his English and then he told me he did not have any patience. Excuse me but I just about died when he, an INSTRUCTOR told me that. I worked at Stanford for 25 years and to hear an instructor say those words was unthinkable. Anyway you can maybe understand my reluctance to ask for help but I need help. Any suggestions?? When I use one of the computers at school everything works just fine. Except I can not get my own computer to log on when I am there. So again that is why I said it is my system and something in my set up that I don't have. Sorry for the long note, I was just letting out a little frustration. LOL Thx for any suggestions, Carolynn Fryer ps: I know this is not the proper way to get ahold of you but I could not find nor have time to find any other way. The UCSC system is not very user friendly

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Wave module
by Alex Krycek Feb. 12, 2015

Feb. 12, 2015

Hello, I'm trying to join two .wav files with the wave module. But when I try to use wave.open(filename, "rb") I receive the following error: Traceback (most recent call last): File "<stdin>", line 1, in <module> File "F:\PortablePython1.0\lib\wave.py", line 483, in open return Wave_read(f) File "F:\PortablePython1.0\lib\wave.py", line 162, in __init__ self.initfp(f) File "F:\PortablePython1.0\lib\wave.py", line 143, in initfp self._read_fmt_chunk(chunk) File "F:\PortablePython1.0\lib\wave.py", line 264, in _read_fmt_chunk raise Error, 'unknown format: %r' % (wFormatTag,) wave.Error: unknown format: 85 I read somewhere that there are various wave formats, only some supported by Python. Is this true? If so, is there any way I can convert my wave files into a supported kind? Thanks!

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[OT] Best Practices for Scientific Computing
by Albert-Jan Roskam Dec. 30, 2014

Dec. 30, 2014

Hi, I thought this might be worth sharing, especially on a windy, rainy Friday evnening: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001… Here are the best practices mentioned in the article: Write programs for people, not computers. A program should not require its readers to hold more than a handful of facts in memory at once. Make names consistent, distinctive, and meaningful. Make code style and formatting consistent. Let the computer do the work. Make the computer repeat tasks. Save recent commands in a file for re-use. Use a build tool to automate workflows. Make incremental changes. Work in small steps with frequent feedback and course correction. Use a version control system. Put everything that has been created manually in version control. Don't repeat yourself (or others). Every piece of data must have a single authoritative representation in the system. Modularize code rather than copying and pasting. Re-use code instead of rewriting it. Plan for mistakes. Add assertions to programs to check their operation. Use an off-the-shelf unit testing library. Turn bugs into test cases. Use a symbolic debugger. Optimize software only after it works correctly. Use a profiler to identify bottlenecks. Write code in the highest-level language possible. Document design and purpose, not mechanics. Document interfaces and reasons, not implementations. Refactor code in preference to explaining how it works. Embed the documentation for a piece of software in that software. Collaborate. Use pre-merge code reviews. Use pair programming when bringing someone new up to speed and when tackling particularly tricky problems. Use an issue tracking tool. Have a great weekend! Regards, Albert-Jan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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Memory management in Python
by Mohamed Ben Mosbah Dec. 9, 2014

Dec. 9, 2014

Hi I'm new to Python and I would like to know how he deals with memory space. I thought I had understood but I made a test and the results were uncoherenent with my understanding, here is the thing: >>> a=[1,2] >>> l=[a,a] >>> id(a); id(l[0]); id(l[1]); 61659528 61659528 61659528 >>> #All Have the same ID >>> l[0]=[0,0] >>> l [[0, 0], [1, 2]] >>> #Why didn't l[1] change as well? >>> id(a); id(l[0]); id(l[1]); 61659528 61390280 61659528 >>> #How come id(l[0]) changed? >>> a = [4,4] >>> l [[0, 0], [1, 2]] >>> #Why didn't l[1] change? l[1] and a were occupying the same memory adress! Thank you for answering :)

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A small project
by Santosh Kumar Dec. 3, 2014

Dec. 3, 2014

Hi All, I am planning to start a small project , so i need some suggestions on how to go about it. 1) It basically takes some inputs like (name,age,course,joining date,remarks) so on. 2) I want a light front end for it. 3) i should be able to query for a particular person on a particular date or a joining date. 4) The app should be easily deployable both in the linux and windows machines. ( something like a .exe in windows) So this is my requirement as stated in the above four points. Now i need suggestions on how to go ahead with these. for 2) should i go for tkinter or do we have something even lighter. for 3) to achieve this should i just go for a database, if yes i need something which can be easily moved across. for 4) if i have to create a executable , how to make sure all the above requirements can be packaged into a application or a software. Thanks in advance. -- D. Santosh Kumar

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(no subject)
by William Dec. 1, 2014

Dec. 1, 2014

Hello there I'm using Python 3.4 running on Ubuntu 14.04LTS I'm new to programming and also new to linux I'm trying to learn the pygame library I was reading : http://programarcadegames.com/index.php?chapter=introduction_to_graphics&la… On the section on how to draw text the writer has the following code | font ||=||pygame.font.SysFont(||'Calibri'||, ||25||, ||True||, ||False||)| |text ||=||font.render(||"My text"||,||True||,BLACK) ||screen.blit(text, [||250||, ||250||]) When I run the code using the IDLE the Python shell gives me the following error Traceback (most recent call last): File "/home/william/Desktop/Pygame/Python 3X/Drawing_Shapes.py", line 48, in <module> font = pygame.font.SysFont('Calibri', 25, True, False) File "/usr/local/lib/python3.4/dist-packages/pygame/sysfont.py", line 614, in SysFont return constructor(fontname, size, set_bold, set_italic) File "/usr/local/lib/python3.4/dist-packages/pygame/sysfont.py", line 537, in font_constructor font = pygame.font.Font(fontpath, size) pygame.error: font not initialized I think the problem is that the fonts in Ubuntu are probably stored in a different location than in Windows OS.And therefore python can not find it using the SysFont method Can anyone give me any suggestion on how to edit the code so that I can write text on my graphics? Thank you. |

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multiprocessing question
by Albert-Jan Roskam Nov. 28, 2014

Nov. 28, 2014

Hi I created some code to get records from a potentially giant .csv file. This implements a __getitem__ method that gets records from a memory-mapped csv file. In order for this to work, I need to build a lookup table that maps line numbers to line starts/ends. This works, BUT building the lookup table could be time-consuming (and it freezes up the app). The (somewhat pruned) code is here: http://pastebin.com/0x6JKbfh. Now I would like to build the lookup table in a separate process. I used multiprocessing. In the crude example below, it appears to be doing what I have in mind. Is this the way to do it? I have never used multiprocessing/threading before, apart from playing around. One specfic question: __getitem__ is supposed to throw an IndexError when needed. But how do I know when I should do this if I don't yet know the total number of records? If there an uever cheap way of doing getting this number? import multiprocessing as mp import time class Test(object): """Get records from a potentially huge, therefore mmapped, file (.csv)""" def __init__(self): self.lookup = mp.Manager().dict() self.lookup_done = False process = mp.Process(target=self.create_lookup, args=(self.lookup,)) process.start() def create_lookup(self, d): """time-consuming function that is only called once""" for i in xrange(10 ** 7): d[i] = i process.join() self.lookup_done = True def __getitem__(self, key): """In my app, this returns a record from a memory-mapped file The key is the line number, the value is a two-tuple of the start and the end byte of that record""" try: return self.lookup[key] except KeyError: # what's a cheap way to calculate the number of records in a .csv file? self.total_number_of_records = 10 ** 7 if key > self.total_number_of_records: if not self.lookup_done: process.join() raise IndexError("index out of range") print "One moment please, lookup not yet ready enough" if __name__== "__main__": test = Test() # check if it works while True: k = int(raw_input("enter key: ")) try: print "value is ", test[k] time.sleep(1) except KeyError: print "OOPS, value not yet in lookup" print "Max key is now", max(test.lookup.keys()) if test.lookup and max(test.lookup.keys()) == (10 ** 7 - 1): print "Exiting" break print "Done" Thank you in advance! Regards, Albert-Jan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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