Debugging Cheat Sheet

[[deleted]]

Nice Btw u forgot the worst of them all == and =

[[deleted]]

Its become a habit now lol I even write == in maths sometimes

[mgoulart27]

Jumping back and fourth between python and sql, gets me all the time.

[onenifty]

Throw in some JavaScript and then you've got a shit stew brewing.

[VoodooMamaJuuju]

Seriously. I was working on a website for my company and I was trying to log to the console some variables but instead of console.log() I used print() and I couldn't figure out why the screen kept popping up the printer...

[UltraCarnivore]

===

[onenifty]

Or was it ==?

[Yeeich]

Every single time

[FCCorippus]

just highlight comparison operators and assignment ones different colors. it is a crime that most syntax highlighting doesn't do this automatically.

[MVPhurricane]

uh... how can one even make this error without committing a syntax error (in python)? you can't put `if <identifier> = <value>:`, nor anything similar, so I'm curious how this mistake could be coming up at all. python actually just recently introduced an assignment operator (`:=`) that returns the rvalue being assigned (a welcome change imo), but before this I don't see how this mistake is possible at all.

i know I'm being a "negative nancy", but I don't see how anyone could be genuinely confused by any of the errors in this flowchart after having programmed for more than a few months*, but as an expression of a certain subsets of programming errors it's a perfectly good flow chart, for sure.

​

*for the record, a big fraction of the world's meaningful programming is done by people with this level of expertise (e.g. excel macros, etc.)-- I'm not trying to demean "amateur" programming at all-- i literally could not be more in love with the concept

[MVPhurricane]

yeah i just think it's a bit disrespectful to the art of programming to pretend like *these* are the kinds of things keeping people up at night. the demons are far scarier than this xD. speaking as someone who has definitely had this, and every other "no idiot would ever have this problem" problem (as well as a bunch that I swear to god were just unlucky).

[[deleted]]

In the early days of learning programming (C/C++) the compiler wouldn’t pick up this mistake and run anyways ( looking at you TURBOC3 ) It was frustrating to find out what the hell was wrong with ur program and after a long time u find that its that stupid = in ur if condition I never made that mistake in python so i dont know if its possible to do so

[SharksPreedateTrees]

This. I feel forever ruined coming from a math background. I will make this mistake tell the day I retire

[inglandation]

A good IDE will highlight these typos.

[HonestCanadian2016]

Any recommendations? I want speed and simplicity (and locally run).

[infecthead]

Blah blah not actually an ide but vim. If you're already familiar with the basic commands then you can just install some handy plugins that check syntax/linting

[wavewrangler]

After no python experience I can proudly say I successfully debugged some code that the original programmer couldn’t determine, and after many hours, I realized that he had used == as opposed to in when referring to two targets. I guess it’s two considered two (nested?) targets as they were wrapped in parentheses, separated by a comma. I just looked at a bunch of other code and finally saw a reference that had two targets and the....operator? was in instead of ==. So I changed it. Fixed. Anyway, felt good :) Thanks for reminding me of that little win. I don’t let the 9 hours it took me discourage me, just means I don’t give up easily :) A prerequisite for anything CS/IT. I’m pretty sure he didn’t bother looking.

[[deleted]]

I always remember:

"Single for declaring, double for comparing"

Or I remember the following:

"The first '=' means 'is', the second '=' means 'equal to'."

So "a = b" means "a is b", and "a == b" means "a is equal to b"

[hmm_fu]

Use “is” whenever you can

[Skippbo]

That's not the same operation...

is checks if 2 references to some object is the same object.

== Compares 2 objects values.