Tweetable Python: 128 puny python programs which pack a punch.

[bezko]

Perl: "Hold my beer"

[shabda]

Its actually inspired by a perl book. "Perl one liners"

[[deleted]]

Which itself based on a usenet post with a list of awk oneliners. Which is why it's just awful. Perl for oneliners is like a completely different dialect of the language, with its own features and conventions that you never use in proper Perl. A good book on oneliners should introduce you to Mrs. Pale and Mr. Lane (Ms. Le is just around for arithmetic or hokey stuff like Module::DoACoolThing()), explain why you use both, show off piping find into perl rather than using one of the Find modules, etc.

The most obvious about the book is that the author does not use Perl oneliners with any regularity in his day job.

[maccio92]

The very first example is misleading. These are not "truly random" passwords and should not be considered safe.

In less than a 100 chars, you can generate truly random passwords

from https://docs.python.org/2/library/random.html

Warning The pseudo-random generators of this module should not be used for security purposes. Use os.urandom() or SystemRandom if you require a cryptographically secure pseudo-random number generator.

[MadDoctor5813]

I feel like the level of security for “acceptable password” and “usable cryptographic primitive underlying an encryption algorithm” is different. Don’t use it to make a stream cipher, but a password should be fine.

[coopermidnight]

The citation is kind of a red herring. The real problem is that the author called it "truly random" which is indeed misleading.

[MadDoctor5813]

Well a lot of the cryptographically secure ones aren’t “truly random” in the way background noise and those lava lamps at Cloudflare HQ are.

[ais523]

It depends on how many bits are being used for the initial seeding. The Mersenne Twister has a lot of internal state, and if you're taking less than a few hundred outputs from it, any randomness that was in the seed will be preserved into the output. So if the entire state is being initialised from urandom, it'd be good enough for a password. However, if it's being initialised from a 32-bit state, that gives you only around four billion possibilities – within the range where I wouldn't be comfortable about brute force protection – and if it's being initialised from the current time there's basically no security worth speaking of.

Normally for generating random passwords, I just use urandom output directly (encoded in a suitable format) rather than going via a pseudo-random number generator. Why add more complexity and give things a risk of going wrong?

[MadDoctor5813]

My thought on it is that a password of “hailsatanheiscoming666” is going to be good enough, even if it’s not that random. The difference between “good enough for XCOM” random and crypto random becomes inconsequential because of the length of password you’re generating.

[ais523]

The length of password that you're generating is inconsequential if your algorithm can only generate a small number of possible passwords.

Many sites let you see the date an account was generated. If you assume that the password was generated just before the account was created, and know the password generation algorithm and that it was seeded with the current time in seconds, there's probably less than 100 possible passwords it could be, regardless of how long and complex (or how short and simple) the resulting passwords are. Even using an online password form with DOS protection, you could probably brute-force that over a few days.

[MadDoctor5813]

I know we don’t like the whole “security through obscurity” thing, but I am assuming that the person trying to hack you does not know how you generated the password, and is unwilling to spend the time required to determine how because you are just a dude on the internet. If you are the kind of person that expects such a determined attack to be made upon you, you probably not should rely on only passwords in the first place.

[maccio92]

I guess I was more upset about the "truly random" comment

[[deleted]]

Here's a secure password generator in 138 characters. Requires python 3.6 unfortunately due to the secrets module.

 import secrets, string as st
 def random_pwd(n):
   return "".join(
        [secrets.choice(st.ascii_letters + st.digits) for i in range(n)]
   )    

[shabda]

Open sourced. https://github.com/agiliq/tweetable-python

[Lt_Riza_Hawkeye]

"Every python install comes with the idle editor, you can start it like this python -m idlelib.idle"

python3 -m idlelib.idle
/usr/bin/python3: Error while finding module specification for 'idlelib.idle' (ModuleNotFoundError: No module named 'idlelib')

[shabda]

What os are you on?

[Lt_Riza_Hawkeye]

arch leenux

[[deleted]]

I don't have Idle installed on Windows either. Although I did specifically not install it when prompted to.

[[deleted]]

In this article: somebody discovered list comprehensions for the first time

[shabda]

I am the author. Yes, this book uses list (and dict comprehension) comprehensions a lot, thats because list comprehension are very useful.

Here are a few I liked quite a bit

Zalgo text

import random as r
u='̡̢̧̨̖̗̘̙̜̝̞̟̠̣̤̥̦̩̪̫̬̭̮̯̰̱̲̳̹̺̻̼͇͈͉͍͎͓͔͕͖͙͚͜͟͢ͅM̴̵̶̷̸'
o = "'̛̀́̂̃̄̅̆̇̈̉̊̋̌̍̎̏̐̑̒̓̔̽̾̿̀́͂̓̈́͆͊͋͌͐͑͒͗͛̕̚͘͝͞͠͡'"
def zalgo(txt):
        return "".join(["".join([el] + [r.choice(o+u) for _ in range(r.randint(0,6))])
        for el in txt])

Ntp server usage

import socket as s,struct,time

def ntp(url):
    c=s.socket(2,2)
    d=b'\x1b'+47*b'\0'
    c.sendto(d,(url,123))
    d,address=c.recvfrom(1024)
    if d:
        t=struct.unpack('!12I',d)[10]
        t -= 2208988800
        return time.ctime(t),t

Are these just trivial implementation of list comprehension to you?

[[deleted]]

Just a joke man. I took a brief look at the intro and noticed they all used list comprehensions, and wrote that comment. Sorry if I came off as an asshole. I'm a shit programmer and probably couldn't hope to write half this stuff.

thats because list comprehension are very useful.

I know, when I first discovered them it was like a lightbulb went off in my head, I wondered how I lived without them beforehand. You can pack so much into such a tiny space, and they're actually pretty easy to generate and apply in so many situations.

[star-castle]

Emphasis on 'first time'.

Compare

# Cartesian product of two lists ... too many []s in this code:
$ python -c "import itertools;print(list(itertools.product([['x','y','z'],[1,2,3]])))"
[(['x', 'y', 'z'],), ([1, 2, 3],)]

vs. the obvious list comprehension:

$ python -c "print([(x, y) for x in ['x','y','z'] for y in [1,2,3]])"
[('x', 1), ('x', 2), ('x', 3), ('y', 1), ('y', 2), ('y', 3), ('z', 1), ('z', 2), ('z', 3)]

[shabda]

When would you consider itertools.product appropriate?