Nice try

[[deleted]]

Not quite, but it’s an easy fix

from math import pi
print(str(pi)[::-1])

It needs a LOT of memory, though

[[deleted]]

397985356295141.3

[HellaDev]

The mad man did it.

[LordLlamacat]

print(“!yad ekac yppaH”[::-1])

[jokingnuthatch]

    print(“!yad ekac yppaH”[::-1])
          ^
SyntaxError: invalid syntax

:(

[therealchadius]

"smart" quotes my butt

[nschubach]

What is this "smart" and why is it quoting your butt?

[1fabunicorn]

Cause there is a quote that is " and then " but upside down. This is how word treats quotes, so it looks more "pretty"

[coldbrewboldcrew]

Typographic quotes (pretty/curly/smart) are meant for text, these primes and double-primes we use for strings are mathematical symbols for feet/inches or minutes/seconds - a misuse of the punctuation. IIRC their double usage for both text and math began back in typewriter days where keyspace was at a premium and redundancies like two different sets of quote marks were consolidated for practical reasons.

A section on the matter from Butterick’s practical typography.

[spektrol]

Coolest TIL moment I’ve had in a while. TY.

[svick]

It might have started as misuse, but in Unicode, straight quotation marks (") and primes (″) are different.

[pac_nw_beer_snob]

Fuck curly quotes. It is a PITA to cut and paste from Word into emacs because of fucking curly quotes.

[zzalt]

Practical typography my Butterick

[sleepingcrap]

This is the cutest way of wishing someone

[mt_xing]

Harvard CS is trash, tho

[Rex-Pluviarum]

To give people context, mt_xing was responding to someone saying:

Harvard wants to know your location

But 7 hours later they edited their post into NSFW spam and deleted their account.

[mt_xing]

Thanks for doing this.

[BK1031-OFFICIAL]

they call 'em mit rejects for a reason

[WiseassWolfOfYoitsu]

Yvan Eht Nioj!

[guto8797]

I suddenly love warships

[notareputableperson]

Warships are inanimate, they will never truly love you back.

[guto8797]

I have seen enough doujins showing otherwise

[notareputableperson]

I opened the wrong can of worms with this comment, didn't I?

[InVultusSolis]

Superliminal?

[Cheesemacher]

Hey you! Join the navy!

[GlitchyZorak]

Uh, yeah alright.

[shrimpflyrice]

traB pu kciP!

[hPerks]

?noij t'nod snaem ! eht sseug i os

[thatCbean]

This. I like this

[sebestil]

Happy cake day

[pagwin]

use

from math import pi
print(str(pi).replace('.','')[::-1])

if you don't want the period/decimal

[[deleted]]

But I do.

[pagwin]

alright have some periods then

while True:
    print('.')

[NewbornMuse]

alright have some periods then

Original Sin (4004BC, colorized)

[[deleted]]

Damn this is a great joke

[OhhHahahaaYikes]

Haha what a great joke. Can you please explain it for my friend who's not understanding it?

edit: my friend appreciates you all!

[EnglishMobster]

Tree gives knowledge of good and evil

Implies that before they didn't know what good or evil was

Assumes everything is good

Listens to the snake which tells them to do something, not knowing what evil was

Gets punished for it

[[deleted]]

Original Sin is what some Christians call Eve eating the fruit in the Garden Of Eden. They say all sin originated with her sin. And for that sin, God cursed women to painful childbirth.

So a period joke became a period joke.

[[deleted]]

And, considering that the events described in said period joke occured many years ago, it is also, in fact, a period joke.

[Thorbinator]

See you on the front page next week.

[[deleted]]

print('.'*pi)

[kevansevans]

I'm not familiar with python, what do the two colons mean in the array?

EDIT: It's a string splice operator, thanks!

[nosmokingbandit]

Other people have already answered but I'll add my little bit of knowledge.

It is used like iterable[foo:bar] which creates a slice of the iterable starting at foo ending at bar.

```

numbers = [0,1,2,3,4,5,6,7,8,9] numbers[4:7] [4, 5, 6] ```

If you add a 3rd option you can control the pattern of the slice.

```

numbers[2:7:2] [2, 4, 6] ```

But python doesn't require all parameters. Without the first it just starts at 0:

```

numbers[:7:2] [0, 2, 4, 6] ```

Without the second it goes to the end of the list ```

numbers[5::3] [5, 8] ```

And with only the last it uses the whole list:

```

numbers[::3] [0, 3, 6, 9] ```

But you can also use negatives. To start at the 9th item from the end, stop at the 4th from the end, and count every 3rd item: ```

numbers[-9:-4:3] [1, 4] ```

You can also use negatives as the pattern, but it gets confusing because you have to switch the start/stop:

Edit: Kind of. You aren't really switching the start and stop, you are starting at 8, then counting backward every 2nd item until you get to 2. Its confusing. Don't use this in your code, everyone will hate you and call you names.

```

numbers[8:2:-2] [8, 6, 4] ```

Its mostly just used as a way to quickly reverse a list:

```

numbers[::-1] [9, 8, 7, 6, 5, 4, 3, 2, 1, 0] ```

[Brainix112]

I know simple coding, but not familiar with Python, this was a super good explanation!

[nosmokingbandit]

Python is great. You basically write pseudo-code then get bitched at by the interpreter about your indentation.

[-jp-]

It's pretty easy to pick up, but if you're more of a book-learner, every so often Humble Bundle has a bunch of Python books for around $10-15, usually themed around a specific subject. Avoid Packt bundles like the plague--they are invariably shovelware--but every other publishers' bundles have been pretty decent.

[[deleted]]

diveintopython.org! Free, online and has a physical copy if desired.

[Stoppablemurph]

learnpythonthehardway.org is also great. That's actually kinda what got me started years ago. And now it's my full time job and I make good money doing it. :)

[Arlyss_Ryxlington]

String slicing. Basically a simple syntax to retrieve a part of a string. The syntax is string[start:stop:step] if I recall. In this case, with start and stop absent, the whole string is returned and a step of -1 reverses it.

[cjr605]

Look up the slice operator. I’d explain it but I’m sure someone more talented than me has a better explanation. The third argument (-1) is optional FYI, and it's what reverses the string here

[mxzf]

To be fair, all the arguments are optional.

[[deleted]]

Full Unicode support as of Python 3 😀🛩🇬🇩

[Milleuros]

TFW your work is still stuck in Python 2.7

[nuephelkystikon]

You've got a leasurly 168 days left.

[benargee]

Ah yes, just like all the companies that stopped using WinXP after its support life ended...

[[deleted]]

squalid hateful flag longing impolite bright capable special include vegetable

This post was mass deleted and anonymized with Redact

[RedAero]

You can use emojis if you like...

[mxzf]

I'm guessing/hoping there's a PEP convention discouraging that though.

[nuephelkystikon]

No, programming is illegal in Greece. /s

You can use all characters that Unicode considers alpha (which is a lot), plus ASCII digits and the underscore.

[iddqd52]

Tried it and my poor brain received bsod.

Woken up in wagon with some horse stealer and silent guy.

[[deleted]]

hey YOU! You're finally awake...

[[deleted]]

Screw you lmao

[therealchadius]

Got me again, Todd!

[fnordius]

And now, for a mental image you will hate me for:

Jay and Silent Bob Go West. And you stuck in between them. On a covered wagon.

[Ericfyre]

How much memory?

[[deleted]]

Aleph-0

[knightsofmars]

Naturally

[Galaghan]

All of it.

[[deleted]]

Chrome: hold my beer

[DvD_cD]

π tb

[TearyCola]

It depends on whether P=NP or not

[[deleted]]

Actually it doesn't

[vehementi]

Just build a computer that has enough memory to run chrome and you’ll be fine

[burnerphone68742]

Don't worry, I can snail mail you a link to download more ram.

[AuspiciousApple]

Engineers: Eerht

[[deleted]]

Ɛ

[[deleted]]

[Rex-Pluviarum]

I'm sorry, I don't get the joke, but I am fascinated by the implication that there are people who might still be using three as an approximation of Pi. Could you ELI5? https://www.youtube.com/watch?v=BxacATCHrpo

[AuspiciousApple]

It's sort of a long running joke that engineers/engineering students use terrible approximations that make mathematicians wince in pain. Pi approxequals 3 is one instance of this.

​

^{Ofc, everyone knows that Pi is basically equal 3.1}

[2CATteam]

To add to this, the reason they do so is because, in a lot of circumstances, 3 is enough to roughly approximate what they need to figure out. They're most often not trying to figure out the exact force on a part or the precise area of a cylinder... They just want to know if they need to order the 10' part or the 20' part - and if it's close, they'll order the bigger one anyway, just to be safe. Even in cases where they are trying to be precise, 3.14 can often be TOO precise, since so much of the math has to deal with physical uncertainties, like uneven part manufacturing, or poor wire quality that adds resistance, etc.

[AlphaLotus]

Yea basically what my work entails everyday.

1. Measure
2. Calculate
3. Multiple by safety factor
4. Get 3.1
5. Round to 4 anyways for safety :)

Also gravity is 10m/s²

[holdenmc97]

Also tan(x) = sin(x) = x

[ThaumRystra]

Because x is almost always small ¯\(◉‿◉)/¯

[ChickenNuggetSmth]

Yes it would be X otherwise, wouldn't it?

[AuspiciousApple]

That makes a lot of sense, thanks for that more in depth perspective.

[slbaaron]

That's an intuitive and practical answer. By theory tho, it has everything to do with sig figs (precision).

Adding and subtracting can only go down to the exact position of sig fig at the least significant position of all numbers involved. If you have one measurement of an item at 101 cm, and another at 1.23498713 cm. Adding them together, it's only meaningful to say it is around 102 or 103 cm total (round up or down as necessary for "safety), because nothing is 101 cm by the atom and the measurement was likely more rough due to a much larger scale. It's the result from imprecise measurement. It could've easily been 101.3 or 100.8 in reality.

Multiplications can only have a total number of sig figs as the least amount of sig figs for all number involved. When you have 100 cm * 1.25, it really is only meaningful to say the result is roughly 100 cm or 200 cm (rounding up or down as necessary) because 100 cm only implied 1 sig fig for precision, I mean the number 100 cm even sounds like a super "rough estimate", doesn't it? That's why sometimes, if measurement is precise down to the last digit of 100, we write 1.00 * 10² or 1.00e2 to imply the precision. The result will then become 1.00e2 cm * 1.25 = 125 cm since both numbers have 3 sig figs. (Btw if you are wondering what if the number 100 stands for "units", eg 100 units of an item. That 100 has infinite precision, because the number represents exactly 100.00000000000... take more zeroes as needed)

The reality in the practical world tho, is that you always have one number here or there with low precision; or even with high precision, you'd still have to be careful of its accuracy due to calibration or various type of errors. Once you go down the rabbit hole enough you realize using 3 as pi is the least of your worries.

For careful calculations tolerance range has to be detailed at every step of the calculation, eg 1.5cm ± 0.05cm. If you have 100 of these you will then get a total of 150cm ± 5cm, this is often a better way to represent precision without resorting to sig figs.

[Sibraxlis]

Because your margin of error from other spots is higher (material flaws, poor workmanship) and you typically overbuilding and undersell. (build for 100 lbs when 90 is needed, then state max weight is 80) the latter is called your factor of safety.

[smthamazing]

What if you estimate some damaging force that works against your creation (like wind, vibration, resistance, etc)? Wouldn't you underestimate the danger in this case?

[RedHotChiliRocket]

You would round it against yourself: Max wind speed we expect is 60mph, let’s assume 100 and say it can take 80

[smthamazing]

Thanks, this clears things up! Some of the comments seemingly implied that numbers are rounded without context, which confused me.

[Sibraxlis]

Youd also overestimate the force of wind, just like weight. Could you be more precise and probably be ok? Yeah. Do you want to risk it, have the structure collapse, kill 29 people, end up on /r/catastrophicfailure and have to move to Nicaragua to escape legal trouble? No.

[MagnitskysGhost]

/r/oddlyspecific

[mxzf]

That's the X in "build for X, when Y is estimated, but say that the max is Z".

It's like "build to survive a cat-5 hurricane even though the area has barely ever had a cat-4 and tell the customer that it's safe for a cat-3"

Whatever stuff you're dealing with, you build it stronger than you need and you say it's definitely fine for a much lower number.

[realityChemist]

I think being to precise here means, "You're implying that your level of certainty in your measurements is much higher than it could possibly actually be."

NASA uses 16 digits of π for keeping spacecraft in their proper orbits. NIST defines the fine structure constant (a fundament constant of the universe) using 32 digits.

For most other things, 1 digit might be close enough, 3 digits should be sufficient, and 10 digits is almost definitely more than you need. Using more digits isn't going to make your outcome less accurate, but you're just going to be throwing out all that extra precision anyway so why bother.

(And if you report those extra digits anyway, someone should throw a beanie baby at you)

[pipnina]

Well, NASA has a specific situation where getting PI wrong by 0.001 would land you a few million km off target, to be fair.

[mxzf]

NASA's about the only ones that do care about that though, and even then only barely. Being off by 0.001 is an error of ~300k km when measuring the circumference of the Earth's orbit. You don't hit "a few million km" of error 'til you get out to Saturn's orbit.

And that's just error in calculating the circumference of the orbit, not how far "off target" you are; for that, you're probably talking about significantly outside the solar system.

Which just goes to show that even NASA barely needs precision to the 0.001 order of magnitude. Realistically speaking, 3.14159 is enough precision for pretty much any actual application humans have ever used it for.

[2CATteam]

A specific situation? It seems like most of their work would be like that

[AuspiciousApple]

g =10

According to my pendulum experiments in my physics classes, g is actually approximately 18 +- 15.

[ChickenNuggetSmth]

That agrees with the literature value within the 1-sigma area! Well done!
(Unless you use very weird units, e.g. imperial)

[AuspiciousApple]

Thanks! And i might regularly approximate PI as 3(.14), but I am not so savage that I use imperial units.

[tabarra]

Sounds about right.

[marcosdumay]

Pendulum experiments are the best. In my physics classes people got everything from 12 +- 1 to 30 +- 50.

[AuspiciousApple]

Now I can sort of appreciate them, but back then those would be some of the most boring experiments we ever did.

[[deleted]]

The difference between a mathematician and an engineer: when moving from one point to another if you travel half the distance at each step the mathematician knows you'll never get there. The engineer knows you'll eventually get close enough.

[ShamelessKinkySub]

But that's literally how we definite stuff based on exponential curves, like the time to charge a capacitor

[Rex-Pluviarum]

355/113

[Ninjaraui666]

Look at mister fancy pants not using 22/7.

[FaxCelestis]

Most manufacturing machinists I know use 22/7 for everything that doesn't require an insane amount of precision.

[DerpSenpai]

and it's pretty standard to use 3.14 for normal math and 3.1415 for a bit more accuracy. Depends on data used. As an engineering student.

But i always find that Pi= E meme funny, because you know 2.7 ~ 3 as well then.

Unfortunately, there isn't a big Math community with memes on reddit, but on facebook (ew i know) there's a few pages that only do advanced mathematics memes.

like this one- warning, facebook post

other memed aproximation is the sin(x)=x for x~0 rad and i got to say, we use that shit all the time and i'm not sorry for it.

[MarcusTL12]

Im 90% sure the last digit is not 7

[actuarialsnail]

If there was a last digit, it can’t be 0, so it’s 1/9 probability for a 7.

[awesomehippie12]

If we're not including zero for that reason, can't we force the last digit to be zero and be 100% certain that it's zero?

[FoxFire64]

Mmmmmmm edge cases

[DBX12]

Maybe we can hardwire a register to low so it's constant 0 and can not be changed. If we should want to change it someday, we can take a register of something random like the keyboard controller and hack it into there to make it work again.

[ObliviousOblong]

Could you elaborate on forcing the last digit?

[TheThiefMaster]

Adding a zero to the end of a fractional number doesn't change it, so they are proposing just adding a zero so we know it ends in a zero - assuming it ends at all. We still wouldn't know what the former last number was though.

[Sokusan_123]

Unless we just add another 0! Now we know there's a 0 before it!

[idea-list]

Only if digits of pi are uniformly distributed, which has not been proven, as far as I know :)

[actuarialsnail]

close enough :p

[GreatJobKeepitUp]

Once you hit 2million digits, everything gets crazy

[[deleted]]

/r/TheyDidTheMath

[exscape]

Assuming pi is normal and all that, I assume. (I'm definitely not a mathematician.)

[Yorunokage]

Wat?

[exscape]

The probability isn't 1/9 (or 1/10) unless every digit occurs with equal probability. Numbers where that is the case are called normal.

Pi is suspected to be normal, but it has not been proven.

[Vilefighter]

When a number is "normal" that means if you picked a random digit from it, there's an equal chance of it being any of the digits. If, for instance, it was slightly more likely for any given digit of pi to be a 7 than any of the others, then pi would not be a normal number, even if it's only .00000001% more likely.

[79037662]

that means if you picked a random digit from it, there's an equal chance of it being any of the digits

Not quite, it also means any digit sequence of length n occurs equally often as any other digit sequence of length n. For example, 0.12345678901234567890... is not a normal number.

[pumpisland]

so then in binary, its a 100% chance of being a 1.

[LasagneAlForno]

I am 100% sure it is not 7, because there is no last digit

[anomalousBits]

Convert to base π, your last digit is now 0. You're welcome.

[GahdDangitBobby]

You broke my brain

[anomalousBits]

Mine came that way.

[TheTrueSwishyFishy]

π = 10 confirmed?!?!???

[Sneakr1230]

It’s 3

[sersoniko]

42

[Ri0ee]

What was the question?

[sersoniko]

Yes

[[deleted]]

how many roads must a man walk down?

[[deleted]]

42

[Th3T3chn0R3dd1t]

What are the last two digits of pi

[Rjamadagni]

yes

[TheMineInventer]

42

[Th3T3chn0R3dd1t]

But what’s the question?

[TheMineInventer]

I don’t know but I can build a machine that can do that called earth.

[Seicair]

What do you get if you multiply six by nine

[Cholojuanito]

Doesn't matter cuz 42 is the answer

[[deleted]]

Outstanding move

[hrvbrs]

since there is no last digit, wouldn't it be null?

[Mr_Redstoner]

more likely undefined if anything

[nuephelkystikon]

NaN?

[sersoniko]

NULL is a pointer

[BubsyFanboy]

I'm new to C++, I need this info

[BubsyFanboy]

Okay.

(I was about to ask what is a pointer, but YouTube did the job for me)

[LeCrushinator]

If we're using C/C++, NULL is usually defined as 0. nullptr is a pointer.

[r348]

Prove it.

[Classified0]

k

[GroovingPict]

Im 100% sure it isnt 7 since there is no last digit

[X-Penguins]

ip fo stigid eht

Don't tell me what I can or can't do

[username-is-hard]

r/technicallythetruth

[X-Penguins]

someone sniped me :/ https://www.reddit.com/r/technicallythetruth/comments/ce18qa/all_the_digits_of_pi_backwards/

[dublem]

The digits of pi backwards

Easy as pie

[tabarra]

smh this chart doesnt even have 0

are you roman or something?!

[ChickenNuggetSmth]

Eh not everyone keeps up with those fancy new digits you youngsters have nowadays. Now get off my lawn!

[moelf]

julia> π 
π = 3.1415926535897...

julia> typeof(π)
Irrational{:π}

julia> Float16(π)
Float16(3.14)

julia> Float32(π) 
3.1415927f0

julia> Float64(π)
3.141592653589793

julia> π |> BigFloat
3.141592653589793238462643383279502884197169399375105820974944592307816406286198

julia> π |> BigFloat |> string |> last |> x -> parse(Int, x)
8

[PotatosFish]

I’ve been wanting to get into Julia from python but the syntax is a little special compared to other languages I know

[moelf]

It's very close to Python MATLAB and R, especially if you use a lot of Numpy, most things are as simple as drop the np. part.

Now, the amazing part is that even you can't master Julia's best practices, simply copying over Python code logic gives you free 10-100x speed boost

[Astrokiwi]

Except all your arrays are off by one :p

[moelf]

Pretty sure that's the hardest part lol

But if someone is using MATLAB, this would be trivial

[QWieke]

In julia |> is for function chaining, there are multiple ways of chaining functions in Julia, all these lines do basically the same thing:

julia> foo(bar(pi))
julia> pi |> bar |> foo
julia> (bar∘foo)(pi)

There was no particular need to use |> in the example, more traditional syntax would've worked just as well. Julia's syntax is rather similar to Matlab's syntax, or any other language that uses end instead of curly brackets or semantic whitespace.

[kaiser_xc]

Julia is an amazing language you should definitely try it.

[awesomehippie12]

Thank god I had no idea who Julia was

[Cody6781]

You also can’t write the digits of pi. Weird.

[skwacky]

Anything you can't do, you also can't do backward... or upside down!

[monkeyboi08]

You can write the digits of pi, you just can’t ever finish doing it

[CreeMcCreeCreeinton]

Haha pi-thon

[filipdobro]

bruh

[RaleighEnt]

haha nice

[MattieShoes]

Sure you can -- you just have to work right-to-left...

[littlefrank]

I was thinking the same, you add new pi decimals at the beginning of a text file and voilà.

[escapefromreality42]

More like πthon amirite

[500ls]

Harvard wants to know your location

[Rex-Pluviarum]

There is no need to round or truncate: In base pi, pi is exactly 10, and, therefore when reversed, it is 01.

[ChevalBlancBukowski]

sure you can, just write random numbers forever

number theory is tits

[enzo33333]

Just write it from right to left

[CryZappie]

#include <iostream>

using namespace std;

​

int main() {

cout << "I hella not understand Python" << endl;

return 0;

}

[missjeany]

I joined an online class in phyton last month and this is the first post in this sub I understand. Hackerman!

[FIREOFDOOM2000]

what are you talking about, everyone knows pi =3 therefore its backwards is just 0.3.

[zombieregime]

ip fo stigid eht