🌐 Mailman 3 June 2019 - Python-list - python.org

Re: Handle foreign character web input
by Jon Ribbens June 29, 2019

June 29, 2019

On 2019-06-28, Chris Angelico <rosuav(a)gmail.com> wrote: > On Sat, Jun 29, 2019 at 6:31 AM Tobiah <toby(a)tobiah.org> wrote: >> A guy comes in and enters his last name as RÖnngren. >> >> So what did the browser really give me; is it encoded >> in some way, like latin-1? Does it depend on whether >> the name was cut and pasted from a Word doc. etc? >> Should I handle these internally as unicode? Right >> now my database tables are latin-1 and things seem >> to usually work, but not always. > > Definitely handle them as Unicode. You'll receive them in some > encoding, probably UTF-8, and it depends on the browser. You can basically assume it is the encoding that the page the form was on was using - which is a good reason to always explicitly specify utf-8 encoding on HTML pages. >> Also, what do people do when searching for a record. >> Is there some way to get 'Ronngren' to match the other >> possible foreign spellings? > > Ehh....... probably not. That's a human problem, not a programming > one. Best of luck. And yet there are many programs which attempt to solve it. The Python module 'unidecode' will do a decent stab of it if the language is vaguely European. Certainly, storing the UTF-8 string and also the 'unidecoded' ASCII string and searching on both is unlikely to hurt and will often help. Additionally using Metaphone or similar will probably also help.

1 0

Use global, or not
by Cecil Westerhof June 29, 2019

June 29, 2019

I have written a GUI program where I have quit a few global variables. I did not like this, so I now use one global dict. Something like: global global_dict canceled_report = 'Genereren rapportage gecanceled.' created_report = 'Rapportage voor {} bestanden is gemaakt.' error_append = 'Er ging iets fout bij het toevoegen van een record.' error_generate = 'Er ging iets fout bij het genereren van de rapportage.' error_select = 'Er ging iets fout bij het selecteren van de directory.' error_widening = 'Er ging iets fout bij instellen van de wijdte.' error_nofiles = 'Er zijn geen bestanden om te verwerken.' messages = { 'canceled': canceled_report, 'created': created_report, 'append': error_append, 'generate': error_generate, 'select': error_select, 'widening': error_widening, 'nofiles': error_nofiles, } error_str = 'Foutmelding' info_str = 'Info' warning_str = 'Waarschuwing' titles = { 'error': error_str, 'info': info_str, 'warning': warning_str, } . . . window = Tk() . . . progress = ttk.Progressbar(progress_frame, orient = 'horizontal', length = 200, mode = 'determinate') . . . global_dict = { 'messages': messages, 'progress': progress, 'window': window, } And in the program do things like: global_dict['progress']['value'] += 1 global_dict['window'].update_idletasks() global_dict['window'].update_idletasks() and: messagebox.showwarning(global_dict['titles']['warning'], global_dict['messages']['nofiles']) Is that an acceptable way to do this? -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

3 2

Re: Handle foreign character web input
by Tobiah June 28, 2019

June 28, 2019

On 6/28/19 1:33 PM, Chris Angelico wrote:> On Sat, Jun 29, 2019 at 6:31 AM Tobiah <toby(a)tobiah.org> wrote: >> >> A guy comes in and enters his last name as RÖnngren. >> >> So what did the browser really give me; is it encoded >> in some way, like latin-1? Does it depend on whether >> the name was cut and pasted from a Word doc. etc? >> Should I handle these internally as unicode? Right >> now my database tables are latin-1 and things seem >> to usually work, but not always. > > Definitely handle them as Unicode. You'll receive them in some > encoding, probably UTF-8, and it depends on the browser. Ideally, your > back-end library (eg Flask) will deal with that for you. It varies by browser? So these records are coming in from all over the world. How do people handle possibly assorted encodings that may come in? I'm using Web2py. Does the request come in with an encoding built in? Is that how people get the proper unicode object? >> Also, what do people do when searching for a record. >> Is there some way to get 'Ronngren' to match the other >> possible foreign spellings? > > Ehh....... probably not. That's a human problem, not a programming > one. Best of luck. Well so I'm at an event. A guy comes up to me at the kiosk and say his name is RÖnngren. I can't find him, typing in "ron" so I ask him how to spell his last name. What does he say, and what do I type?

3 2

Re: change spacing to two instead of four with pep8 or flake8?
by shivam.patel＠lendbuzz.com June 28, 2019

June 28, 2019

On Tuesday, April 8, 2014 at 8:55:46 AM UTC-4, Peter Otten wrote: > Dennis wrote: > > > In Pylint you can change the spacing multiplier from 4 spaces to two > > in its pylintrc, but for the life of me I cannot find a way to do this > > with the flake8 / pep8 utilities. > > > > I want to avoid ignoring E111 altogether if at all possible, because > > it may catch other spacing problems that are not as obvious. > > > > hacky/non-hacky solutions welcome of course. > > The check is hardcoded > > if indent_char == ' ' and indent_level % 4: > yield 0, "E111 indentation is not a multiple of four" > > so your only short-term solution is to modify the script's source code. What file is this?

1 0

Re: How do you insert an item into a dictionary (in python 3.7.2)?
by Jon Ribbens June 28, 2019

June 28, 2019

On 2019-06-28, Larry Martell <larry.martell(a)gmail.com> wrote: > On Fri, Jun 28, 2019 at 11:10 AM CrazyVideoGamez ><jasonanyilian(a)gmail.com> wrote: >> >> How do you insert an item into a dictionary? For example, I make a dictionary called "dictionary". >> >> dictionary = {1: 'value1', 2: 'value3'} >> >> What if I wanted to add a value2 in the middle of value1 and value3? > > Dicts are not ordered. If you need that use an OrderedDict > (https://docs.python.org/3.7/library/collections.html#collections.OrderedDict) This is no longer true from Python 3.6 onwards - dicts are ordered. There's no way to insert an item anywhere other than at the end though.

2 1

Make sure the window title is visible in tkinter
by Cecil Westerhof June 28, 2019

June 28, 2019

I need to write a desktop program. I choose to use tkinter. How can I make sure the window title is visible? For example when I have the following code: from tkinter import Button, filedialog, Label, messagebox, Tk window = Tk() window.title('A long window title') Button (window, text = 'Short text').pack() window.mainloop() I see only a part of the 'A', but I would like to see the complete: 'A long window title' -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

5 7

Re: Only a message at the highest exception
by Cecil Westerhof June 28, 2019

June 28, 2019

Cameron Simpson <cs(a)cskk.id.au> writes: > On 28Jun2019 12:17, Cecil Westerhof <Cecil(a)decebal.nl> wrote: >>Chris Angelico <rosuav(a)gmail.com> writes: >>> On Fri, Jun 28, 2019 at 7:33 PM Cecil Westerhof <Cecil(a)decebal.nl> wrote: >>>> I have a tkinter program where I have a function generate_report >>>> which >>>> in a try block calls the function append_row. This function has also a >>>> try block. When they get an exception they give message. But when >>>> append_row has already given a message then generate_report should >>>> not. To implement this I use the following class: >>>> >>>> class AlreadyHandledException(Exception): >>>> pass >>>> >>>> Then in append_row I have: >>>> except Exception as err: >>>> messagebox.showerror(error_str, >>>> error_append + '\n\n\n\n' + str(err)) >>>> raise AlreadyHandledException() >>>> >>>> And in generate_report I have: >>>> except Exception as err: >>>> if type(err).__name__ != "AlreadyHandledException": >>>> messagebox.showerror(error_str, >>>> error_generate + '\n\n\n\n' + str(err)) >>>> progress.pack_forget() >>>> >>>> Is this an acceptable way, or should I do it differently? >>> >>> Well, first off, I would use two separate except clauses, rather than >>> a type check. >> >>You are completely right. >> >>> But are you able to just NOT catch the exception inside >>> append_row? Let it be handled at the top level only. >> >>I am giving different messages. I changed the top part to: >> except AlreadyHandledException: >> pass >> except Exception as err: >> messagebox.showerror(error_str, error_generate + '\n\n\n\n' + str(err)) >> progress.lower() > > For contrast, another approach. > > By catching AlreadyHandledException and just going "pass" you're > effectively swalling that exception. For your purpose, that works. > > However, in a since, why raise an exception you _know_ you're going to > deliberately ignore? I am not. I am using it to quit generating the report. Just ignoring that I could not append a record does not sound correct to me. Yes they got a message that something went wrong. But if there is still a generated report, things will go wrong. > What if you have append_row return a Boolean? True on success, False on > failure but situation handled (i.e. append_row has shown an error, or > whatever recovery you adopt). And keep the uncaught exceptions for the > _unhandled_ situation. The "exceptional" situation. > > Example: > > def append_row(...): > ... > try: > ...stuff... > except ExpectedExceptionHere as err: > messagebox.showerror(....) > ...maybe some cleanup... > return False > ... > return True > > Then your generate_report code goes: > > try: > appended = append_row(....) > except Exception as err: > messagebox.showerror(....) > else: > if appended: > hooray! > else: > unhappy, but continuing And that is exactly what I not want to do. -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

1 0

Re: Only a message at the highest exception
by Cecil Westerhof June 28, 2019

June 28, 2019

Chris Angelico <rosuav(a)gmail.com> writes: > On Fri, Jun 28, 2019 at 7:33 PM Cecil Westerhof <Cecil(a)decebal.nl> wrote: >> >> I have a tkinter program where I have a function generate_report which >> in a try block calls the function append_row. This function has also a >> try block. When they get an exception they give message. But when >> append_row has already given a message then generate_report should >> not. To implement this I use the following class: >> class AlreadyHandledException(Exception): >> pass >> >> Then in append_row I have: >> except Exception as err: >> messagebox.showerror(error_str, >> error_append + '\n\n\n\n' + str(err)) >> raise AlreadyHandledException() >> >> And in generate_report I have: >> except Exception as err: >> if type(err).__name__ != "AlreadyHandledException": >> messagebox.showerror(error_str, >> error_generate + '\n\n\n\n' + str(err)) >> progress.pack_forget() >> >> Is this an acceptable way, or should I do it differently? >> > > Well, first off, I would use two separate except clauses, rather than > a type check. You are completely right. > But are you able to just NOT catch the exception inside > append_row? Let it be handled at the top level only. I am giving different messages. I changed the top part to: except AlreadyHandledException: pass except Exception as err: messagebox.showerror(error_str, error_generate + '\n\n\n\n' + str(err)) progress.lower() -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

2 1

Re: Hiding a progressbar in tkinter
by Cecil Westerhof June 28, 2019

June 28, 2019

MRAB <python(a)mrabarnett.plus.com> writes: > On 2019-06-26 16:47, Cecil Westerhof wrote: >> I just started with GUI stuff in tkinter. I have a progressbar, but I >> want it to be only visible when it is used. So I tried the following: >> window = Tk() >> window.title(window_str) >> frame = Frame(window) >> frame.pack(side = "top", fill = "both", expand = True) >> Button(window, text = button_str, command = select_dir).pack() >> progress = ttk.Progressbar(window, orient = "horizontal", length = 200, >> mode = "determinate") >> progress.pack() >> progress.lower(frame) >> window.mainloop() >> >> But that does not hide the progressbar. What am I doing wrong? >> >> I could use pack_forget, but that will change the dimensions of the >> window. >> > The progress bar isn't hidden because there's nothing on top of it to > hide it. > > import tkinter as tk > import tkinter.ttk as ttk > > window = tk.Tk() > window.title(window_str) > frame = tk.Frame(window) > frame.pack(side='top', fill='both', expand=True) > tk.Button(window, text=button_str, command=select_dir).pack() > > # Create a frame to hold the progress bar. > progress_frame = tk.Frame(window) > progress_frame.pack(fill='x', expand=True) > > # Put the progress bar into the progress frame, ensuring that it fills > the grid cell. > progress = ttk.Progressbar(progress_frame, orient='horizontal', > length=200, mode='determinate') > progress.grid(row=0, column=0, sticky='nsew') > > # Now put a blank frame into the progress frame over the progress bar, > ensuring that it fills the same grid cell. > blank = tk.Frame(progress_frame) > blank.grid(row=0, column=0, sticky='nsew') > > # Raise the progress bar over the blank frame to reveal it. > progress.tkraise() > > # Lower the progress bar underneath the blank frame to hide it. > progress.lower() > > window.mainloop() Works like a charm. Thanks. -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

1 0

Only a message at the highest exception
by Cecil Westerhof June 28, 2019

June 28, 2019

I have a tkinter program where I have a function generate_report which in a try block calls the function append_row. This function has also a try block. When they get an exception they give message. But when append_row has already given a message then generate_report should not. To implement this I use the following class: class AlreadyHandledException(Exception): pass Then in append_row I have: except Exception as err: messagebox.showerror(error_str, error_append + '\n\n\n\n' + str(err)) raise AlreadyHandledException() And in generate_report I have: except Exception as err: if type(err).__name__ != "AlreadyHandledException": messagebox.showerror(error_str, error_generate + '\n\n\n\n' + str(err)) progress.pack_forget() Is this an acceptable way, or should I do it differently? -- Cecil Westerhof Senior Software Engineer LinkedIn: http://www.linkedin.com/in/cecilwesterhof

2 1