Mailman 3 February 2021 - Python-list

>>> %matplotlib inline results in SyntaxError: invalid syntax
by Mike S Dec. 25, 2023

Dec. 25, 2023

I have installed Python 3.4.4 on XPSP3 and am trying to work my way through this tutorial. A Complete Tutorial on Ridge and Lasso Regression in Python http://www.analyticsvidhya.com/blog/2016/01/complete-tutorial-ridge-lasso-r… In Step 2 "Why Penalize the Magnitude of Coefficients?" we are shown this code: #Importing libraries. The same will be used throughout the article. import numpy as np import pandas as pd import random import matplotlib.pyplot as plt %matplotlib inline I get an error on the last line. I am running this code in Idle Python 3.4.4 Shell... Python 3.4.4 (v3.4.4:737efcadf5a6, Dec 20 2015, 19:28:18) [MSC v.1600 32 bit (Intel)] on win32 Type "copyright", "credits" or "license()" for more information. >>> import numpy as np >>> import pandas as pd >>> import random >>> import matplotlib.pyplot as plt >>> %matplotlib inline SyntaxError: invalid syntax What am I doing wrong? Suggested reading? TIA, Mike

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Re: How to add CC and BCC while sending mails using python
by akegb3＠gmail.com June 20, 2023

June 20, 2023

On Tuesday, September 30, 2008 8:00:16 AM UTC-8, Bernhard Walle wrote: > Hi, > > * cindy jones [2008-09-30 19:57]: > > > > Can someone tel me how to add cc's and bcc's while sending mails using > > python > > Following (tested) snippet should help: > > ------------------ 8< ------------------------------ > from smtplib import SMTP > from email.mime.image import MIMEImage > from email.mime.text import MIMEText > from email.mime.multipart import MIMEMultipart > > to = 'to_address(a)example.invalid' > cc = 'cc_address(a)example.invalid' > bcc = 'bcc_address(a)example.invalid' > > msg = MIMEMultipart() > msg['To'] = to > msg['Cc'] = cc > msg['From'] = 'bernhard(a)bwalle.de' > msg['Subject'] = 'Test' > text = MIMEText('Das ist ein Test') > text.add_header("Content-Disposition", "inline") > msg.attach(text) > > s = SMTP('test.smtp.relay') > s.sendmail(msg['From'], [to, cc, bcc], msg.as_string()) > s.quit() > ------------------ >8 ------------------------------ > > > Regards, > Bernhard Hello Bernhard, I've tried the above code and the bcc address does not receive the message, on the To & CC addresses receive it. Here are snippets from my code, perhaps something will stand out to you? to = 'ed(a)domain.gov' cc = 'ed(a)gmailmail.com' bcc = 'ed(a)home.net' msg = MIMEMultipart() msg['To'] = to msg['Cc'] = cc msg['Subject'] = 'My Subject text here' msg['From'] = 'edsboss(a)domain.gov' smtp = SMTP("smtpserver") smtp.ehlo() smtp.sendmail(msg['From'], [to, cc, bcc], msg.as_string()) Thanks in advance..hope you're still out there!! ~Ed

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Re: error of opening Python
by Mladen Gogala May 2, 2022

May 2, 2022

On Fri, 26 Feb 2021 02:23:51 -0500, Terry Reedy wrote: > Not on Windows. Please don't spew misleading garbage that will only > confuse the new user on a different operating system. > You are right, I apologize. I sort of like poking fun at the Winduhs users but this is not the right place. -- Mladen Gogala Database Consultant https://dbwhisperer.wordpress.com

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Re: code blocks in Python
by hungjunglu＠yahoo.com March 25, 2022

March 25, 2022

Skip Montanaro <skip(a)pobox.com> wrote in message news:<mailman.1035.1069703636.702.python-list(a)python.org>... > > You should be able to express the desired semantics of your extension to the > language without requiring us to execute code. I have yet to see an > explanation of why you want > > def c: > x += 1 > > added to the language. I can guess that it binds c to a "code block". How > do I use it? The above is illegal syntax in Python today. Am I supposed to > guess how to use it? That has nothing to do with compile(). Am I supposed > to run it with the exec statement or do you envision me just inserting > > c > > into my code? Skip: being you a Python old timer, I think you are just grumbling for no good reason. :) Before anything else, people are already jumping into implementation details, optimization, syntax, etc. I am barely starting to look at whether there have been previous existing efforts, and if so, why were they discarded, etc. > > What exactly have you given me that I couldn't have done with > > x = 1 > x += 1 > I come back again to repeat it one more time: the compile() function already exists and works in Python. Before you do your posting, please think about the compile() function first. (Do I need to say it one more time? I don't mind.) So, let me try to pretend I am Skip Montanaro, and follow through with the process. (a) OK, I have been told that compile() function exists in Python. (b) I am complaining that I can do x = 1 x += 1 without resorting to codeblocks. So there is no need for codeblocks. Codeblocks are useless, good for nothing. (c) OK, one more time, I have been told that compile() function exists and works in Python. Everytime I talk about codeblocks, I need to think about the compile() function first. (d) Aha! So by analogy, there is no need for the compile() function in Python. I get it now! (e) Wait a second... searching through the Python newsgroup archive I find hundreds if not thousands of messages related to the usage of the compile() function. So the compile() function can't be useless. Either thousands of Python users are wrong, or I have not been careful in my thinking process. (f) Hmm... let me look at those messages and try to understand how people are using the compile() function. (g) Aha! The compile() function is not useless. I know how to use it, now. (h) Aha! Codeblocks are not useless. (i) Aha! So codeblocks are analogous to the compile() function, the only difference is that codeblocks are compiled at compile time. The compile function compiles the code string at runtime. (j) Wait, I think Hung Jung has said everything before in his messages. Bingo! Now you get it. Hung Jung

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Converting py files to .exe and .dmg
by Brian Simms Feb. 18, 2022

Feb. 18, 2022

Hi there, I have done a lot of looking around online to find out how to convert Python files to .exe and .dmg files, but I am confused. Could someone provide pointers/advice as to how I can turn a Python file into a Windows .exe and Mac .dmg file. Thanks for any help.

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Pickle file and send via socket
by S.B Feb. 18, 2022

Feb. 18, 2022

Hello friends Does anyone know if it's possible to pickle and un-pickle a file across a network socket. i.e: First host pickles a file object and writes the pickled file object to a client socket. Second host reads the pickled file object from the server socket and un-pickles it. Can anyone provide a simple code example of the client and server sides? Thanks

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count consecutive elements
by Bischoop Sept. 27, 2021

Sept. 27, 2021

I want to to display a number or an alphabet which appears mostly consecutive in a given string or numbers or both Examples s= ' aabskaaabadcccc' output: c # c appears 4 consecutive times 8bbakebaoa output: b #b appears 2 consecutive times I thought about set the string then and for each element loop the string to check if equal with element set element if so count =+1 and check if next to it is not equal add counter value to list with same index as in set. However I'm fighting to code it and the counting numbers are not right: s = 'aabskaaabadcccc' c = 0 t = set(s) # set of characters in s li=[0,0,0,0,0,0] # list for counted repeats for x in t: h = t.index(x) for i in s: if i == x: m = s.index(i) c +=1 if s[m+1] != x: # if next element is not x if c > li[h]: li[h]= c c = 0 for i in t: n = t.index(i) print(i,li[n]) -- Thanks

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Re: Compute working days
by Casey Webster Aug. 19, 2021

Aug. 19, 2021

How about: from datetime import date, timedelta # Define the weekday mnemonics to match the date.weekday function (MON, TUE, WED, THU, FRI, SAT, SUN) = range(7) def workdays(start_date, end_date, whichdays=(MON,TUE,WED,THU,FRI)): ''' Calculate the number of working days between two dates inclusive (start_date <= end_date). The actual working days can be set with the optional whichdays parameter (default is MON-FRI) ''' delta_days = (end_date - start_date).days + 1 full_weeks, extra_days = divmod(delta_days, 7) # num_workdays = how many days/week you work * total # of weeks num_workdays = (full_weeks + 1) * len(whichdays) # subtract out any working days that fall in the 'shortened week' for d in range(1, 8 - extra_days): if (end_date + timedelta(d)).weekday() in whichdays: num_workdays -= 1 return num_workdays

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Re: Simple question - end a raw string with a single backslash ?
by Mladen Gogala April 24, 2021

April 24, 2021

On Mon, 19 Oct 2020 02:44:25 +0000, Stefan Ram wrote: > Mladen Gogala <mgogala(a)yahoo.com> writes: >>In Perl, there are no classes. > > If there are no classes in Perl, then what does > > bless REF,CLASSNAME > > do? bless \$ref will make the given reference a reference to the class. And classes is Perl are called "modules". However, Perl classes are not the classes in the real sense. There is no inheritance. You can have a similar thing in C: it's called "struct", it can do similar things like Perl modules. But C isn't object oriented. Inheritance is an essential characteristic of object orientation. There were attempts to turn Perl into OO language with Moose (https://metacpan.org/pod/Moose) However, Moose is complex, tedious and rarely used. Perl6 is an OO language, but nobody uses it. The problem is CPAN and all the Perl5 modules which are not compatible with Perl6 or "Roku" as it is known. -- Mladen Gogala Database Consultant http://mgogala.byethost5.com

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weirdness with list()
by Cameron Simpson March 12, 2021

March 12, 2021

I just ran into a surprising (to me) issue with list() on an iterable object. My object represents an MDAT box in an MP4 file: it is the ludicrously large data box containing the raw audiovideo data; for a TV episode it is often about 2GB and a movie is often 4GB to 6GB. For obvious reasons, I do not always want to load that into memory, or even read the data part at all when scanning an MP4 file, for example to recite its metadata. So my parser has a "skip" mode where it seeks straight past the data, but makes a note of its length in bytes. All good. That length is presented via the object's __len__ method, because I want to know that length later and this is a subclass of a suite of things which return their length in bytes this way. So, to my problem: I've got a walk method which traverses the hierarchy of boxes in the MP4 file. Until some minutes ago, it looked like this: def walk(self): subboxes = list(self) yield self, subboxes for subbox in subboxes: if isinstance(subbox, Box): yield from subbox.walk() somewhat like os.walk does for a file tree. I noticed that it was stalling, and investigation revealed it was stalling at this line: subboxes = list(self) when doing the MDAT box. That box (a) has no subboxes at all and (b) has a very large __len__ value. BUT... It also has a __iter__ value, which like any Box iterates over the subboxes. For MDAT that is implemented like this: def __iter__(self): yield from () What I was expecting was pretty much instant construction of an empty list. What I was getting was a very time consuming (10 seconds or more) construction of an empty list. I believe that this is because list() tries to preallocate storage. I _infer_ from the docs that this is done maybe using operator.length_hint, which in turn consults "the actual length of the object" (meaning __len__ for me?), then __length_hint__, then defaults to 0. I've changed my walk function like so: def walk(self): subboxes = [] for subbox in self: subboxes.append(subbox) ##subboxes = list(self) and commented out the former list(self) incantation. This is very fast, because it makes an empty list and then appends nothing to it. And for your typical movie file this is fine, because there are never _very_ many immediate subboxes anyway. But is there a cleaner way to do this? I'd like to go back to my former list(self) incantation, and modify the MDAT box class to arrange something efficient. Setting __length_hint__ didn't help: returning NotImplemeneted or 0 had no effect, because presumably __len__ was consulted first. Any suggestions? My current approach feels rather hacky. I'm already leaning towards making __len__ return the number of subboxes to match the iterator, especially as on reflection not all my subclasses are consistent about __len__ meaning the length of their binary form; I'm probably going to have to fix that - some subclasses are actually namedtuples where __len__ would be the field count. Ugh. Still, thoughts? I'm interested in any approaches that would have let me make list() fast while keeping __len__==binary_length. I'm accepting that __len__ != len(__iter__) is a bad idea now, though. Cheers, Cameron Simpson <cs(a)cskk.id.au>

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