Don't Write Code Like THIS In Python 😡

Please always remember this when you're coding in #Python. #Shorts

[@josemata8865]

What about "if user:" or "if not user" for these kind of condition?

[@xE92vD]

if not user: would be the one if you wanted to do something if user is empty, None, etc. Since None, null, empty string is all False.

[@fumano2679]

if not user isnt same because it will also trigger when user is an empty strong, list, dict, ... and also if user == False

[@333HaKan333]

If user != “”

[@doltramir]

@@fumano2679 and if it's 0, 0.0, 0j (int, float and complex respectively)

[@doltramir]

@@333HaKan333 bad idea. "hello" != "" - True None != "" - also True if string is not None: ... - is the best way here.

[@jonhjorturbrjansson9052]

How about just 'if user:'?

[@not_vinkami]

This can be a little bit unclear, but it works

[@_sabritos]

@@not_vinkami Not at all cases : if the Node equal to 0 it would be False not True

[@Nofxthepirate]

This is usually only used when the condition variable is a boolean because the behavior becomes less clear with other data types

[@BboyKeny]

@@Nofxthepirate if not not user: Now it's a boolean for sure

[@nyther]

"if user" would return True because the string would be evaluated by its lenght, which in this case is above 0

[@TheDutchisGaming]

Love how the third variant already has squiggles noting something irregular probably.

[@Indently]

Real men ignore the squiggles

[@grubbygeorge2117]

@@Indently that’s why women are better at coding. Never ignore the squiggles!!

[@DaniPaunov]

There seem to be a fair number of comments about a few things 1. Why not "if user" I'm fairly certain that can give you false without user being none 2. What about "if user != None" checking for equality with None is generally not good practice. furthermore, from what I've read, it's possible for classes to redefine that to have special behaviour in both cases, it doesn't matter whether the code is shorter, it matters whether it's readable. a lot of people are likely to find those less readable.

[@opus_X]

In what scenario does "if user" give false even if the string isn't empty.

[@zeldaplayergl11]

If user: will always be true as long as there is a value. Whether user is None or a Falsy value, you'll most likely handle it the same way. So it's often not a problem

[@StephenRayner]

Only the first one is acceptable. And you should invert it and return or throw if user is None to handle the incorrect usage.

[@tb15900]

Don’t use number 2 either. Stick to convention, you’ll see the first in codebase everywhere; readability and speed of understanding is key

[@doltramir]

if not x is y -- is two operations: logical 'is', and logical 'not'. Same idea as if you did this: if not x == y if x is not y -- is one operation: logical 'is not' Again, same idea as: if x != y Get rid of redundant 'not'.

[@jkljosh7392]

I feel like you'd instead check if the user is None then print a error and stop the code instead of only running code if it is

[@QckSGaming]

Here's the coder that got past junior!

[@deidarasan2760]

Lol second one killed me

[@ryanzwe]

It's a PowerShell standard

[@SP-db6sh]

Plz Make a series on PEP guidelines & refactoring with custom pylint setup ! is it possible to customise pylint & change code automatically if error detected ?

[@Indently]

I’ll look into it! I haven’t eBen thought about a spellcheck for coding, usually because I think that if anything is done automatically, that can lead to some very well hidden bugs in our code that we wouldn’t even notice. I’ll do some research on it though.

[@nathanhessling7841]

use if user: in this case, it also protects against empty strings, dicts, lists, sets, etc. only time not to do it this way is if working with ints where 0 is valid because 0 is falsy. that is if you want a non-falsy value.

[@NoProblem76]

Google says "if not user" is preferred when possible. Unless explicit check is required

[@lengors7327]

"if not user" isn't equivalent to "if user is not None" since the former evaluates to true when user is none, but also something with a length of 0 (dicts, lists, etc) or false or 0, while the latter only evaluates to true if user is none and only none.

[@grubbygeorge2117]

@@lengors7327 Isn’t evaluating to false when the user is empty the preferred outcome most of the time? You wouldn’t want to put empty user names in your database

[@lengors7327]

@@grubbygeorge2117 that scenario happens only when you're first receiving input from the user in which case user will never be None and will always be a string. In that case you're better of testing the length of the string since, most of the time, you actually want something thats larger than 2/3 characters... when dealing with databases, tipically (although not always) user would only be none when querying it (for a single user) and the database doesnt find any match in which case you get none. In this case you either receive an user object or none. So checking for none is enough... but yes, you could also simply use "if not user"/"if user", I wasnt saying that you should never use that sort of check, just that its different from checking "is none" and that you should know the difference or you might, unintenionally, introduce bugs in your code

[@imperial2069]

Ok so ill do my best to confuse people reading my code , thx for this advice

[@rajveersingh-ix6ti]

this is on a different level. > user = "Mark" > user and print(user)

[@denizsincar29]

myfunction that returns true for success and false on error: (get_file('url') and print('success')) or print('error')

[@hackerulroman]

what happens when we use 100% of our brains:

[@denizsincar29]

@@richardpaulhall it is only awailable with dynamicly typed langs.

[@jambonmusical2689]

Ok, Always go for what will bother people the most, got it

[@gabrielmaimonie7005]

Thank you

[@drrenard1277]

I do believe that python allows that for those programming in other national languages where subject, verb, noun, etc are not in same order as English.

[@fluffykitties9020]

😮 in python, if a string(or any object) is empty it evaluates to None, which python considers falsy". so all you need is.. >>> if user: which will return False if the str, or list, or dict is empty.🎉

[@Indently]

That is False, it does not evaluate to None, it evaluates to False

[@fluffykitties9020]

@@Indently that part of my answer is incorrect, thanks for the correction, but my answer is stll correct.

[@siddharth4838]

Thank you! Loving your videos!

[@xxlarrytfvwxx9531]

My VSCode never yelled at me about this.

[@badonker]

I refuse to think that people use 3rd variant pretty much unreadable

[@peckychicken]

What about if user not is none?

[@ben_jammin242]

I think old school programmers would prefer if !(user == None) or if (user != None) over if (None != User). Either way, that's a bad way to check for empty strings. Afaik an empty string is still a string, it's not None...

[@hectormoreno-bravo8399]

What is MOST READABLE

[@dc22199x]

The first if is normal, the 2nd one is called Yoda condition as in like master yoda in star wars, the 3rd one no one that I know uses that especially in opensource community 😅

[@Indently]

I just took the 3rd one right from the PEP documentation for things you should never do 😂

[@joergsonnenberger6836]

The only reason the third way works is because it is actually parsed as "not (a is None)" instead of "(not a) is None". Given that most Python programmers won't know the operator precedence between "not" and "is" by heart, that's a no-go.

[@gbpekalp]

What is this font

[@kamranview9465]

Love you brother

[@Nofxthepirate]

This reminds me of the time I learned you can reference array elements in C by saying index[array] instead of array[index]

[@joergsonnenberger6836]

That's an important code golf technique, because you can use the operand inside [] for assignments without any extra spaces :), e.g. "1[a=b]".

[@dhyan_a]

I have a doubt what if we do if user != ' ': print(user) Same output, but is this a bad practice?

[@ntlake]

Just use: if not user:... For the cases (like this one) where the user can't be a falsy value like 0 or "".

[@zeldaplayergl11]

Me: If not user:

[@SurCreVlad]

C guys at the same time: if (user) printf("%s", user);

[@chrislbaird]

Is none the same as null?

[@officialacescottie]

If user not in ['', None, "None"] Or just use regex

[@LuvxJacqu4li8e]

The power of python

[@franmedina2096]

Why not “if user:”, much simpler

[@nineteenn7866]

“if user:” is readable to me

[@VelocityWIS]

Thanks

[@zxw]

if user: print(user) ?

[@Indently]

That is clean, but shouldn't be mixed up with explicitly checking if something is not None.

[@artemetra3262]

this would also include the case when user = '' which is *not* None

[@Indently]

​@@artemetra3262 With not None, we're looking that the variable is explicitly not None, it doesn't matter if it's empty, that's a different thing. I could have picked a better example for sure though, oh well, live and learn. "" is not None returns True None is not None returns False But the video is not about that ahah. It's really about how you should be formulating your logic...

[@artemetra3262]

@@Indently yes, i know that, which is why i said that the method provided by John is not the same as an explicit comparison to None

[@Indently]

​@@artemetra3262 Ah, I couldn't tell what you meant ahah, then just ignore the paragraph I wrote 😅

[@tarunshetty3434]

which editor is this?

[@Dalmen]

PyCharm

[@dvoltaire]

How about if user: print(user)

[@frankv0]

User isn’t a boolean so it would just give an error

[@fortznite8150]

@@frankv0 what do you mean, it doesnt give any error?

[@frankv0]

@@fortznite8150 yea I realized that after I commented it lol

[@junkynioy]

Baby yoda:

[@abhijithnt7177]

An empty string in a variable means Fasle.

[@altairbueno5637]

If user usually does the thing

[@snopz]

if user != None: print(user)

[@rbxneko]

How about "user != None"?

[@CeciEstUnIdentifiantYouTube]

And what about "if user!=None :" it works right ?

[@Indently]

No that's wrong, you want to compare the instance, not the value, that's why you use "is".

[@joergsonnenberger6836]

If user is a class that provides __eq__, all bets are off.

[@mikhailmiller9262]

Why not just: if user: print(user)

[@kamranview9465]

Thanks for sharing this information

[@gtxg.]

Just do if user:

[@FirstNameLastName-gh9iw]

I’m definitely weirded out by python syntax, is not is weird, and the for loops are the worst

[@CrjaseMechaEngr]

Or just “if not user”

[@Indently]

You'd think so at first, but that's actually a very common mistake.

[@lakshraja4831]

This mostly happens when you learn other languages like of the c family where it is written as != Null. Plus for us it is more readable but we forgot that there are python programmers who cry over such small things.

[@Indently]

Python programmers cry over evvveeeerrryyything 😂

[@lakshraja4831]

@@Indently lol

[@imrannooraddin1876]

better advice: use the assert keyword in a try except clause. try: user = input() assert user is not none # rest of code except AssertionError: #handle the error

[@adiveler]

if Baba is not you:

[@AkivaB]

I just use if user:

[@dcknature]

if user is not None: makes the most sense to me. Other variants are good for Yoda. Size matters not. Look at me. Judge me by my size, do you? Hmm? Hmm. And well you should not. For my ally is the Force, and a powerful ally it is. Life creates it, makes it grow. Its energy surrounds us and binds us. Luminous beings are we, not this crude matter. You must feel the Force around you; here, between you, me, the tree, the rock, everywhere, yes. Even between the land and the ship. YODA, TO LUKE SKYWALKER

[@Indently]

😂

[@sniperdaoud]

if user None is not 🤔

[@V1kToo]

if user: print(user)

[@SirenGlitch]

If user !None:

[@Dalmen]

this will not work. my you mean !=

[@shlokbhakta2893]

If user is not not user

[@Dalmen]

Syntax Error!

[@jasonmnayerji1783]

Isn't it simpler to say if user: Condition

[@jack_papel]

This is not identical. If user = 0, for example, it will not run, despite 0 being not None

[@jasonmnayerji1783]

@@jack_papel I see what your getting at. However in this scenario considering we are dealing with strings, the only way the conditional evaluates to false is if the string is empty in which case we wouldn't want to execute the condition.

[@Indently]

If you're only dealing with strings sure, but user can be anything, even it's own object.

[@prabhatmishra8422]

Me who is using: if user != None: print(user) 🤣🤣🤣🤣🤣🤣

[@Indently]

PEP & the official Python documentation doesn't recommend what you did, mostly because it's the wrong use of "!=" and you should be using "is"

[@prabhatmishra8422]

@@Indently i don't change anything if it works 🤣🤣

[@GlobeTrekMoto]

if user != None: is better

[@weirddev]

if user:

[@platinvm_]

if user: >>>>

[@MariusCiurea1]

Why not 'if user'? Cos it's gonna evaluate bool(user) which is True, so it prints out the user

[@Indently]

Depends on what you are coding, 'if user' & 'if not None' are very different and do not perform the same check. That's up to the programmer though which functionality they want for which context.

[@MariusCiurea1]

@@Indently I see, but this particular case, bool(None) is also False, so it can be used like this. if you make the user to point out to an empty string, the condition within the if will be True, printing out nothing. Indeed, if you just want to compare to None, I agree with you 😁

[@Indently]

@@MariusCiurea1 When making this video I didn't expect to get so much attention regarding the variable itself, I was just trying to show the proper order for creating not None checks. I will pick a better example next time :)

[@MariusCiurea1]

@@Indently I see. I said I agree with you. Even though I use python for years, I've learned new stuff from your videos. Keep it up!

[@Indently]

@@MariusCiurea1 Happy to have you as a follower! Definitely don't be afraid to point anything out, I'm always happy to learn something new.

[@sandiguha]

definitely the user isn't none, because they don't use computers in church.

[@denizsincar29]

whaaat? i was writing if user!=None: wow. you made my day.

[@LaughingOrange]

Python likes to swap cryptic symbols for English. It's part of what makes it great for new learners.

[@denizsincar29]

@@LaughingOrange look to applescript and it'll be another level of english: set x to random number from 1 to 100 display dialog 'what is the number?' default answer '' set y to text returned of the result if x is equal to y then display dialog 'you guessed'

[@QckSGaming]

None of these are the most readable way. Guard clauses man, learn them and save all of our time

[@thecringequeen31]

User ifn’t none: print(Mario)

[@ronaldodimaano8641]

`bool(None)` returns False so you can just do `if user:` or `if not user:`

[@gigachad8810]

bool({}) also returns False, so does bool(""). you might have noticed that both of those are not None

[@moon911x]

it's funny 😃

[@ewerybody]

lol everybody is like `if user:`!!! Nobody sees that `not user` will never be `None` so the last statement will ALWAYS print! 😂

[@Indently]

A lot of people don't know the difference between "is" & "==", but I also gave a poor example for beginners, while what I mentioned in the video is correct, I can see why people would try to be smart about it and shorten it. Even if it's wrong and "NOT" the same thing 😅

[@ewerybody]

@@Indently well, its about intend! If I WANT to catch user being other than None OR "" `if user:` is fine!

[@AquaQuokka]

Never let them know your next move... if user is None: return else: ...

[@not_vinkami]

At least it isn't "not user == None"

[@Indently]

It’s not even Halloween yet and you’re already scaring me !

[@notzack6438]

Damn python looks weird (I only learned c++ thus far)

[@itsmaxim01]

the correct way to do this is simply not coding in python

[@memereview7415]

Doesnt None work the same as False, and if so why not use "if not user:",

[@Dalmen]

because it is not doing the same. you may use "if user:" But even this is not the same, because a empty string will as well give a True back.

[@vinnythelegend]

Just do if user: Lol

[@Dalmen]

bevor you laught at other, make sure you give a right answer. "if user:" don't do the same! A empty string will give here a FALSE as well back.

[@vinnythelegend]

@@Dalmen You thought you were smart coming at me like that. You know what, I think I'm smart too. Therefore I actually went and tested it in Python myself. Both my example and the one in this video work the same, as I initially implied (both return False if the string is empty). Feel free to verify it yourself, if you even have Python installed... lol

[@Yankzy]

Just say IF USER:

[@Indently]

As long as you know the difference between if user is not None, and if user, you can do whatever you want.

[@alext5497]

If (user) Yw

[@gdmathguy]

Wahoo user

[@rootya.]

import this

[@zdwlees]

If user != None: :)

[@ginomcfino4639]

The language is designed to handle the third way learn how to read code

[@therodentous]

its abolutely useless the most readeble and right is: if user:

[@Indently]

It really depends, I think not knowing the difference between "user is not None" & "if user" is a really amateur mistake, considering they do 2 completely different things.

[@pigeoni2]

"is not" haha ever heard of "!="

[@Indently]

You don't use != with None (PEP)

[@onlymeok]

!= is an inequality test, "is not" tests for object identity which is faster.

[@ewerybody]

@@onlymeok `is` tests for identity! `not` negates to either True or False ☝️🤓

[@mm552]

What about: "user != None:" Also seems pretty readable. (And it's shorter)

[@th2th210]

Most useless advice ever, just use if user ????????????

[@jiaxiangchen3500]

haha,I wii write to def you_name(user): return 'your name'+user

[@pandasoli6581]

if user: print(user)

[@johannesweber9410]

if user:

[@callmelord]

if user: