4 ms·

A key hallmark of Python is readability - which this cheat sheet has managed to royally screw up. It looks more like an XML cheatsheet at first glance. I work

by FZ1 7y ago

A key hallmark of Python is readability - which this cheat sheet has managed to royally screw up. It looks more like an XML cheatsheet at first glance. I work in python full-time for a living, and found myself having to re-examine several times to make sense of this wacky, non-standard notation. ------- Edit: Keep in mind there's a standard way to represent these options in a clear, consistent manner (lists, sequences, optional args). No need to re-invent something that's hard to read and understand. See: https://docs.python.org/3/library/stdtypes.html#sequence-types-list-tuple-range https://docs.python.org/3/library/stdtypes.html#sequence-typ...

Lendal 7y ago
I think this is for people who already know Python, and just need a quick memory aid. I agree for a complete and correct reference I would recommend the documentation, as you said. A proper cheatsheet takes liberties for the sake of achieving both brevity and comprehensiveness at the same time.
wyattpeak 7y ago
While I agree the notation is a bit weird, I disagree that there is any standard notation for types. The Python docs in particular fail for exactly one of the things I like about TFA - it tells you the type of the output of each function in its angle-bracketed style. Take, for example, the definition of the operation s[i:j] in the Python docs: the result is "slice of s from i to j". Is that the same type as the input? Is it an iterator? No information. I doubt most people are confused about the output, but a reference is specifically for people who are uncertain about how a function works.
- FZ1 7y ago
  You're right that there is not any official standard. But almost every major library follows a convention that's very similar to the cpython docs. If you're making a language reference, shouldn't it look like the language ?
nixpulvis 7y ago
the hallmark is readability?! really!? Please explain to me why then you introduce a binding after you use it in array comprehensions. [x*2 for x in range(1,10)]
- pyuser583 7y ago
  Functional programming?
  - nixpulvis 7y ago
    I wouldn't call this a functional argument, per se, although many functional languages encourage the kind of syntax I'm advocating for here. And some may not... Basically I write things like `data.map(|x| ...).filter(|x| ...)`, or just `data.fold(|x| ...)` and I'm quite happy.
- vharuck 7y ago
  As a person who majored in math, this is very readable.
  - nixpulvis 7y ago
    As a person who often struggled in math for perhaps many reasons, this was a common issue for me. First you define things, then you use them. No other rule makes sense generally, and I challenge anyone to prove me wrong. Now is a simple set like { 2x : x ∈ ℝ } going to confuse me, probably not... but when variables are just thrown around all willy nilly, I get confused pretty quick.
  - saeranv 7y ago
    I never understood list comprehensions, and was always slightly resentful of (in my mind) their illogical ordering until I realized they were mimicking mathematical expressions.
- Igelau 7y ago
  In one of your math courses you'll eventually run across what they call "set builder notation. The notation for this is a decent example that shouldn't be too hard to follow. What it's basically saying is {2x: x∈[1,10)} with the implication that x is an integer. We usually read the colon (or sometimes a vertical bar) as "such that". I know my explanation is somewhat lacking, but you can probably see the parallels there. You'll probably get to it this year or next.

by FZ1 7y ago

Lendal 7y ago

I think this is for people who already know Python, and just need a quick memory aid. I agree for a complete and correct reference I would recommend the documentation, as you said. A proper cheatsheet takes liberties for the sake of achieving both brevity and comprehensiveness at the same time.

wyattpeak 7y ago

While I agree the notation is a bit weird, I disagree that there is any standard notation for types. The Python docs in particular fail for exactly one of the things I like about TFA - it tells you the type of the output of each function in its angle-bracketed style. Take, for example, the definition of the operation s[i:j] in the Python docs: the result is "slice of s from i to j". Is that the same type as the input? Is it an iterator? No information. I doubt most people are confused about the output, but a reference is specifically for people who are uncertain about how a function works.

FZ1 7y ago
You're right that there is not any official standard. But almost every major library follows a convention that's very similar to the cpython docs. If you're making a language reference, shouldn't it look like the language ?

nixpulvis 7y ago

the hallmark is readability?! really!? Please explain to me why then you introduce a binding after you use it in array comprehensions. [x*2 for x in range(1,10)]

pyuser583 7y ago
Functional programming?
- nixpulvis 7y ago
  I wouldn't call this a functional argument, per se, although many functional languages encourage the kind of syntax I'm advocating for here. And some may not... Basically I write things like `data.map(|x| ...).filter(|x| ...)`, or just `data.fold(|x| ...)` and I'm quite happy.
vharuck 7y ago
As a person who majored in math, this is very readable.
- nixpulvis 7y ago
  As a person who often struggled in math for perhaps many reasons, this was a common issue for me. First you define things, then you use them. No other rule makes sense generally, and I challenge anyone to prove me wrong. Now is a simple set like { 2x : x ∈ ℝ } going to confuse me, probably not... but when variables are just thrown around all willy nilly, I get confused pretty quick.
- saeranv 7y ago
  I never understood list comprehensions, and was always slightly resentful of (in my mind) their illogical ordering until I realized they were mimicking mathematical expressions.
Igelau 7y ago
In one of your math courses you'll eventually run across what they call "set builder notation. The notation for this is a decent example that shouldn't be too hard to follow. What it's basically saying is {2x: x∈[1,10)} with the implication that x is an integer. We usually read the colon (or sometimes a vertical bar) as "such that". I know my explanation is somewhat lacking, but you can probably see the parallels there. You'll probably get to it this year or next.