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Search - "python debugger"
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Very specific and annoying situation here:
- Working on a machine learning project with other people
- I'm on Linux, they use Windows
- We code in python
- We generally use vscode for development, and its python extension
I implement some basic neural networks with tensorflow, and add a bunch of logging for it. I test it on my machine and it works fine.
But, my group mates report that "after a few seconds the entire client hangs".
Apparently it only happens on Windows?
We start debugging the hell out of the code I implemented, added 20 log messages and sat there for a solid hour.
Until I make one very odd realization: the issue doesn't happen when I run the script in my terminal, instead of vscode with the debugger. So I try different debug settings, using an external terminal instead of vscode's built in debug console seems to fix it too.
And I make another observation: In the debug console, some messages don't seem to appear at all, while the external terminal shows them just fine.
So, turns out, that printing an epsilon character: “ε” (U+03B5), causes the entire thing to hang up.
It's the year 2020 and somehow we still can't do unicode.
I'm so done, what on earth.9 -
[long]
When searching for internship via school I found this small startup with this cute project of building a teaching tool for programming. There were back then 2 programmers: the founder and the co-founder.
Then like 1 week before the internship started, the co-founder had a burnout and had to get off the project, while the company was so low on budget the founder, aka my new b0ss, had to work separate jobs to keep the company alive. (quite metal tbh)
It's funny because I'm a junior developer, 100%. I've been coding as a hobby for around 8 years now but I've never worked in a big company before. (No exception to this workplace either)
First project I get: rewrite the compiler. The Python compiler.
"But wait, why not just embed a real compiler from the first case?"
-nanananana it's never simple, as you probably know from your own projects.
The new compiler, as compared to existing embedded compiler solutions out there, needed these prime features:
- Walk through the code (debugger style), but programmatically.
- Show custom exceptions (ex: "A colon is needed at the end of an if-statement" instead of "Syntax error line 3")
- Have a "Did-you-mean this variable?" error for usage of unassigned variables.
- Be able to be embedded in Unity's WebGL build target
All for the use case of being a friendly compiler.
The last dash in the list is actually the biggest bottleneck which excluded all existing open-source projects (i could find). Compliant with WebAssembly I can't use threads among other things, IL2CPP has lots of restrictions, Unity has some as well...
Oh and it should of course be built using test-driven development.
"Good luck!" - said the founder, first day of work as she then traveled to USA for **3 weeks**, leaving me solo with the to-be-made codebase and humongous list of requirements.
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I just finished the 6th week of internship, boss has been at "HQ" for 3 weeks now, and I just hit the biggest milestone yet for this project.
Yes I've been succeeding! This project has gone so well, and I'm surprising myself how much code I've been pumping out during these weeks.
I'm up now at almost 40'000 lines of source and 30'000 lines of code. ‼
( Biggest project I've ever worked on previously was at 8'000 lines of code )
The milestone (that I finished today) was for loops! As been trying to showcase in the GIF.
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It's such a giant project and I can honestly say I've done some good work here. Self-five. Over-performing is a thing.
The things that makes me shiver though is that most that use this application will never know the intricates of it's insides, and the brain work put into it.
The project is probably over-engineered. A lot. Having a home-made compiler gives us a lot of flexibility for our product as we're trying to make more of a "pedagogic IDE". But no matter that I reinvented the wheel for the 105Gth time, it's still the most fun I've had with a project to date.
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Also btw if anyone wants to see source code, please give me good reasons as I'm actively trying to convince my boss to make the compiler open-source.
Cheers!4 -
Two big moments today:
1. Holy hell, how did I ever get on without a proper debugger? Was debugging some old code by eye (following along and keeping track mentally, of what the variables should be and what each step did). That didn't work because the code isn't intuitive. Tried the print() method, old reliable as it were. Kinda worked but didn't give me enough fine-grain control.
Bit the bullet and installed Wing IDE for python. And bam, it hit me. How did I ever live without step-through, and breakpoints before now?
2. Remember that non-sieve prime generator I wrote a while back? (well maybe some of you do). The one that generated quasi lucas carmichael (QLC) numbers? Well thats what I managed to debug. I figured out why it wasn't working. Last time I released it, I included two core methods, genprimes() and nextPrime(). The first generates a list of primes accurately, up to some n, and only needs a small handful of QLC numbers filtered out after the fact (because the set of primes generated and the set of QLC numbers overlap. Well I think they call it an embedding, as in QLC is included in the series generated by genprimes, but not the converse, but I digress).
nextPrime() was supposed to take any arbitrary n above zero, and accurately return the nearest prime number above the argument. But for some reason when it started, it would return 2,3,5,6...but genprimes() would work fine for some reason.
So genprimes loops over an index, i, and tests it for primality. It begins by entering the loop, and doing "result = gffi(i)".
This calls into something a function that runs four tests on the argument passed to it. I won't go into detail here about what those are because I don't even remember how I came up with them (I'll make a separate post when the code is fully fixed).
If the number fails any of these tests then gffi would just return the value of i that was passed to it, unaltered. Otherwise, if it did pass all of them, it would return i+1.
And once back in genPrimes() we would check if the variable 'result' was greater than the loop index. And if it was, then it was either prime (comparatively plentiful) or a QLC number (comparatively rare)--these two types and no others.
nextPrime() was only taking n, and didn't have this index to compare to, so the prior steps in genprimes were acting as a filter that nextPrime() didn't have, while internally gffi() was returning not only primes, and QLCs, but also plenty of composite numbers.
Now *why* that last step in genPrimes() was filtering out all the composites, idk.
But now that I understand whats going on I can fix it and hypothetically it should be possible to enter a positive n of any size, and without additional primality checks (such as is done with sieves, where you have to check off multiples of n), get the nearest prime numbers. Of course I'm not familiar enough with prime number generation to know if thats an achievement or worthwhile mentioning, so if anyone *is* familiar, and how something like that holds up compared to other linear generators (O(n)?), I'd be interested to hear about it.
I also am working on filtering out the intersection of the sets (QLC numbers), which I'm pretty sure I figured out how to incorporate into the prime generator itself.
I also think it may be possible to generator primes even faster, using the carmichael numbers or related set--or even derive a function that maps one set of upper-and-lower bounds around a semiprime, and map those same bounds to carmichael numbers that act as the upper and lower bound numbers on the factors of a semiprime.
Meanwhile I'm also looking into testing the prime generator on a larger set of numbers (to make sure it doesn't fail at large values of n) and so I'm looking for more computing power if anyone has it on hand, or is willing to test it at sufficiently large bit lengths (512, 1024, etc).
Lastly, the earlier work I posted (linked below), I realized could be applied with ECM to greatly reduce the smallest factor of a large number.
If ECM, being one of the best methods available, only handles 50-60 digit numbers, & your factors are 70+ digits, then being able to transform your semiprime product into another product tree thats non-semiprime, with factors that ARE in range of ECM, and which *does* contain either of the original factors, means products that *were not* formally factorable by ECM, *could* be now.
That wouldn't have been possible though withput enormous help from many others such as hitko who took the time to explain the solution was a form of modular exponentiation, Fast-Nop who contributed on other threads, Voxera who did as well, and support from Scor in particular, and many others.
Thank you all. And more to come.
Links mentioned (because DR wouldn't accept them as they were):
https://pastebin.com/MWechZj912 -
For fucks sake python.
Reminder to the morons like me still using python:
Notepad++ is not a real IDE and Console output is not a real debugger.
And here we see the absolutely dogshit worthless error output of python:
Says its the fucking return line where the problem is. Besides the problem being between my fucking ears apparently, it took a fucking double take to realize I had capitalized the class keyword.16 -
Do not use a "debugger".
A debugger is like doing a full-body scan of a sick person. You do not get any specific useful information, and you find a whole lot of information that doesn't help and is just confusing.
Source: Learn Python The Hard Way
Your thought on it?7 -
Textbook definition of insanity is debugging in Spyder
While True:
Do:
#Comment out code
Run
If not BUG:
Comment back in
Else:
Print('Congratulations. You found it. Just kidding. It's not THIS line. It's just the combination of lines')
Does anyone have a suggestion for a good python debugger that allows jumping to statements, etc.?2 -
If I ever work with people who use Python professionally I will go postal in under a day they are some of the most unprofessional snarky little fucking bastards on the internet !
Apparently a question with a million hits who's cure all answer DOESN'T WORK, is me being stupid.
So question, how many of you when looking at a third party client that doesn't have great documentation, export class data into a file to look it over at your leisure by using a serializer that just dumps the shit into said file so you can look at it ?
I mean fire and forget. Just works. Just descends into the data structure and starts dumping field values. Done. One line of code.
Json.PUTMYSHITINASTRING(FUCKINGCLASS) ???????
DON'T SAY MY METHOD OF WORKING IS BAD ! ESPECIALLY WHEN THERE FUCKING EXPORT CODE AS A CHECK_CIRCULAR BOOLEAN PARAMETER INDICATING IT SHOULD WORK BETTER THAN IT FUCKING DOES AND THE FUCKING DEBUGGER CAN REFLECT THE OBJECT !!!!4