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

EuroPython 2019: Beginners’ Day Workshop
by M.-A. Lemburg June 20, 2019

June 20, 2019

If you’re new to Python, you should come to our friendly, welcoming and helpful Beginners’ Day Workshop. We cater to new Pythonistas of all levels: from absolute beginners through to experienced programmers encountering Python for the first time. * https://ep2019.europython.eu/events/beginners-day/ * What is Beginners’ Day ? ------------------------ Beginners’ day welcomes and supports folks who are new to Python programming. It takes place on Tuesday 9th July, from 9:30 - 16:00 at the workshop venue, FHNW Campus Muttenz. Just in time to get you ready for all the talks which follow on Wednesday, Thursday and Friday ! It’s also a great place to make friends with fellow attendees and figure out how to get the most out of EuroPython. Bring your laptop, because this will be a hands-on session! The day will start with workshops to give you the chance to try out Python in lots of different situations: making a game, creating a website, programming embedded devices or telling stories with data (in a Jupyter notebook). Later in the day you’ll have an opportunity to further explore those aspects of Python which appeal to you with the support of a team of experienced and helpful mentors. We’ll end the day with a question and answer session about Python, EuroPython and the wider Python ecosystem. The emphasis will be in creating a fun, supportive and useful path into the Python programming language and its community. Sign up for Beginners’ Day -------------------------- You will need a conference pass to attend, but otherwise, it’s free, so if you’re thinking of coming to the conference, but you’re new to Python or programming, this could be the session for you: https://ep2019.europython.eu/registration/buy-tickets/ The session will be presented in English (although our mentors will typically speak a few other languages as well). If you’d like to come, please do register in advance for this session, so that we know how to plan to make it the best yet. We need to know the numbers for planing the workshop. Sign up for Beginners’ Day here: https://docs.google.com/forms/d/e/1FAIpQLScBSJ8y--ROBI7HDQ01H1Cn9RI9amC9mRo… Call for Mentors ---------------- The workshop is being organised by experienced Python programmer and educator, Nicholas H.Tollervey. Already know Python? Do you value working in an open, inclusive and collaborative way? Want to develop your mentorship skills? Fantastic! We’re looking for folks with the technical skills, patience, humour and empathy to work with beginners who may come from a wide variety of backgrounds and levels of experience. It’s rewarding, fun and a great way to give back to the community. We’d especially love to hear from you if you can add an extra language to help non-English speakers feel comfortable asking questions, or if you’ve never mentored before and want to try to share your knowledge for the first time. This is a supportive environment for both beginner programmers AND beginner mentors. :-) Please sign up as a mentor on our mentor registration form: https://docs.google.com/forms/d/e/1FAIpQLSdkphUVi_vplS7yvxI432R03BJPCapv-K2… Dates and Venues ---------------- EuroPython will be held from July 8-14 2019 in Basel, Switzerland, at the Congress Center Basel (CCB) for the main conference days (Wed-Fri) and the FHNW Muttenz for the workshops/trainings/sprints days (Mon-Tue, Sat-Sun). Tickets can be purchased on our registration page: https://ep2019.europython.eu/registration/buy-tickets/ For more details, please have a look at our website and the FAQ: https://ep2019.europython.eu/faq Help spread the word -------------------- Please help us spread this message by sharing it on your social networks as widely as possible. Thank you ! Link to the blog post: https://blog.europython.eu/post/185723885512/europython-2019-beginners-day-… Tweet: https://twitter.com/europython/status/1141675177400590336 Enjoy, -- EuroPython 2019 Team https://ep2019.europython.eu/ https://www.europython-society.org/

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tkinter: widget to display set returned from database table
by Rich Shepard June 20, 2019

June 20, 2019

In a database application I want to design a view for the table rows returned from a select statement. Tkinter has a listbox widget and web searches suggest that multicolumn listboxes are best based on ttk.Treeview widgets, but my understanding of a treeview is to display a hierarchical set rather than a simple list. Each table has multiple columns and I want to create a view for each table that will allow the user to select a row. The SQL select statement will be formed from criteria provided in a separate dialog box. Advice needed, Rich

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s.sendall(filename + "\r\n") TypeError: a bytes-like object is required, not 'str'
by vakul bhatt June 19, 2019

June 19, 2019

Hi Team, i m new to python, running below program, getting error Python Version : 3.7 32bit for windows Program: ============================ #simple Goopher client import socket, sys port = 70 host = sys.argv[1] filename = sys.argv[2] s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) s.sendall(filename + "\r\n") while 1: buf = s.recv(2048) if not len(buf): break sys.stdout.write(buf) ============================ Error : ============================ python goopher.py quux.org / Traceback (most recent call last): File "goopher.py", line 13, in <module> s.sendall(filename + "\r\n") TypeError: a bytes-like object is required, not 'str' ============================ please help. thanks & Regards

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Understand workflow about reading and writing files in Python
by Windson Yang June 19, 2019

June 19, 2019

I'm trying to understand the workflow of how Python read/writes data with buffer. I will be appreciated if someone can review it. ### Read n data 1. If the data already in the buffer, return data 2. If the data not in the buffer: 1. copy all the current data from the buffer 2. create a new buffer object, fill the new buffer with raw read which read data from disk. 3. concat the data in the old buffer and new buffer. 4. return the data ### Write n data 1. If data small enough to fill into the buffer, write data to the buffer 2. If data can't fill into the buffer 1. flush the data in the buffer 1. If succeed: 1. create a new buffer object. 2. fill the new buffer with data return from raw write 2. If failed: 1. Shifting the buffer to make room for writing data to the buffer 2. Buffer as much writing data as possible (may raise BlockingIOError) 2. return the data

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[RELEASE] Python 3.7.4rc1 and 3.6.9rc1 are now available
by Ned Deily June 19, 2019

June 19, 2019

Python 3.7.4rc1 and 3.6.9rc1 are now available. 3.7.4rc1 is the release preview of the next maintenance release of Python 3.7, the latest feature release of Python. 3.6.9rc1 is the release preview of the first security-fix release of Python 3.6. Assuming no critical problems are found prior to 2019-06-28, no code changes are planned between these release candidates and the final releases. These release candidates are intended to give you the opportunity to test the new security and bug fixes in 3.7.4 and security fixes in 3.6.9. We strongly encourage you to test your projects and report issues found to bugs.python.org as soon as possible. Please keep in mind that these are preview releases and, thus, their use is not recommended for production environments. You can find the release files, a link to their changelogs, and more information here: https://www.python.org/downloads/release/python-374rc1/ https://www.python.org/downloads/release/python-369rc1/ -- Ned Deily nad(a)python.org -- []

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EuroPython 2019: Community Discounts
by M.-A. Lemburg June 18, 2019

June 18, 2019

The EuroPython Society (EPS) does not only run the EuroPython conference, but also aims to provide help for the Python community in Europe in general. * https://www.europython-society.org/ * Let’s all meet at EuroPython ---------------------------- In addition to the Python Organizers Lunch (see previous post), which focuses on conference organizers, we are also establishing a program to support attendees of Python user groups and conferences in Europe. We’d like to invite all of you to EuroPython 2019 this year. Of course, we cannot give out free tickets to everyone, but we can at least recognize your participation in the Python community by giving out discounts for the conference. * https://ep2019.europython.eu/ * Discounts for EuroPython Tickets -------------------------------- If you are running a Python event (conference or user group) in Europe, please reach out to board(a)europython.eu to request a coupon code for your group, which you can then pass on to your group members or attendees. If you are not running a user group or conference, but a regular attendee of one, please contact your organizers to have them submit a request. We can only distribute codes at the user group and conference organizer level. The coupon codes are valid for conference tickets bought starting today and will give you a 10% discount on the ticket price (both regular and late bird prices). The codes are setup for user group sizes of between 30-50 members, but we are also extending this to organizers and attendees of larger conferences. If you need a code valid for larger groups, please mention this in your email. Dates and Venues ---------------- EuroPython will be held from July 8-14 2019 in Basel, Switzerland, at the Congress Center Basel (CCB) for the main conference days (Wed-Fri) and the FHNW Muttenz for the workshops/trainings/sprints days (Mon-Tue, Sat-Sun). Tickets can be purchased on our registration page: https://ep2019.europython.eu/registration/buy-tickets/ For more details, please have a look at our website and the FAQ: https://ep2019.europython.eu/faq Help spread the word -------------------- Please help us spread this message by sharing it on your social networks as widely as possible. Thank you ! Link to the blog post: https://blog.europython.eu/post/185683252247/europython-2019-community-disc… Tweet: https://twitter.com/europython/status/1141044869470871553 Enjoy, -- EuroPython 2019 Team https://ep2019.europython.eu/ https://www.europython-society.org/

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EuroPython 2019: Inviting European Python Conference Organizers
by M.-A. Lemburg June 18, 2019

June 18, 2019

As you may know, the EuroPython Society (EPS) has extended it’s mission to not only run the EuroPython conference, but also provide help for the Python community in Europe in general. * https://www.europython-society.org/ * As part of this, we would like to get to know, and help create closer ties between organizers of other European Python events. Organizers’ Lunch ----------------- We would like to invite representatives of all European Python conference to EuroPython 2019 to join us for an organizers’ lunch. We’re planing the lunch for Thursday or Friday. Details will be announced closer to the event. Our aim is to get to know each other, exchange experience in organizing events and to find out how we, as EPS, can most effectively help other conferences going forward. Free Tickets ------------ To support and facilitate this, we are giving out one free conference ticket per conference team, so that each team can send a representative to the organizers’ lunch. If your team wants to send someone to join, please write to board(a)europython.eu, mentioning the conference you’re organizing and some background on your team. Dates and Venues ---------------- EuroPython will be held from July 8-14 2019 in Basel, Switzerland, at the Congress Center Basel (CCB) for the main conference days (Wed-Fri) and the FHNW Muttenz for the workshops/trainings/sprints days (Mon-Tue, Sat-Sun). Tickets can be purchased on our registration page: https://ep2019.europython.eu/registration/buy-tickets/ For more details, please have a look at our website and the FAQ: https://ep2019.europython.eu/faq Help spread the word -------------------- Please help us spread this message by sharing it on your social networks as widely as possible. Thank you ! Link to the blog post: https://blog.europython.eu/post/185683241297/europython-2019-inviting-europ… Tweet: https://twitter.com/europython/status/1141044706979274752 Enjoy, -- EuroPython 2019 Team https://ep2019.europython.eu/ https://www.europython-society.org/

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tkinter: on_cancel() method
by Rich Shepard June 18, 2019

June 18, 2019

I have frames for data entry and modification. Each has two buttons: Save and Cancel. Is there a standard tkinter on_cancel() method responding to a user clicking on the Cancel button? My web searches find suggestions for 'after' responses, but no specific code to close the dialog box without saving any data. Using return and close() generate errors. TIA, Rich

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Re: Is there an archive of this list with permanent URLs to each message?
by jkn June 18, 2019

June 18, 2019

On Monday, June 17, 2019 at 10:28:44 AM UTC+1, Luciano Ramalho wrote: > Hello! When I wrote Fluent Python a few years ago I provided my > readers with hundreds of links to my sources, including several links > to messages in the python-list archive. > > Now as I prepare the 2nd edition I notice all my links to this list > are broken. Apparently mailman rebuilds the archives and changes the > ids of the messages. > > Is there an archive of python-list that preserves each message with a > permanent URL? > > Thanks! > > Luciano > > PS. For the curious, here is an instance of the problem. The message > currently at: > > https://mail.python.org/pipermail/python-list/2009-February/525280.html > > Used to be at this URL: > > https://mail.python.org/pipermail/python-list/2009-February/538048.html > > > > -- > Luciano Ramalho > | Author of Fluent Python (O'Reilly, 2015) > | http://shop.oreilly.com/product/0636920032519.do > | Technical Principal at ThoughtWorks > | Twitter: @ramalhoorg A second edition? Curses, just after I recently bought a copy of the first edition ;-o ... (It's a very good book BTW - thanks!) J^n

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python numpy histogram
by Machiel Kolstein June 18, 2019

June 18, 2019

Hi, I get the following error: ERROR: Traceback (most recent call last): File "exponential_distr.py", line 32, in <module> numpy.histogram(data_array, bins=100, range=20000) File "/usr/lib/python2.7/dist-packages/numpy/lib/function_base.py", line 499, in histogram mn, mx = [mi + 0.0 for mi in range] TypeError: 'int' object is not iterable with the code shown below. I guess I am using "numpy.histogram" below. Also, is there a way to fill the histogram on an event by event base without using the clumsy way of constructing an array as I do below? And - final question - how can I most easily plot the histogram without having to define - again - the bins etc...? CODE: import numpy import numpy.random rate = float(1e5) average_dt = 1.0/rate print "average dt: ", average_dt calc_average = 0.0 total_num=1000.0 isFirst = True for index in range(0, int(total_num)): time = numpy.random.exponential(average_dt) # print "time: ", time, " = ", time*1e9, " ns" calc_average = calc_average + time # Idiot python way of constructing an array (God, I hate python...) if (isFirst == True): data_array = time isFirst = False else: data_array = numpy.hstack((data_array, time)) calc_average = calc_average/total_num print "calculated average: ", calc_average, " = ", calc_average*1e9, " ns" print "data_array: ", data_array numpy.histogram(data_array, bins=100, range=20000) # import matplotlib.pyplot as plt # plt.hist(data_array, bins=100, range=20000) # plt.show() -- Avís - Aviso - Legal Notice - (LOPD) - http://legal.ifae.es <http://legal.ifae.es/>

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