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0 pointssolox34y ago0 comments

Notice that, in the original quote,

    There should be one-- and preferably only one --obvious way to do it.

the author used two different ways of hyphenating (three, if you count the whole PEP 20). PEP 20 is clearly not meant to be taken as law. Nor PEP 8. Nor PEP 257.

People frequently mistake "one obvious way" with "one way". There are lots of ways to iterate through something, for example, but there is really one obvious way. And the philosophy here still applies: when you read anyone else's python code, the obvious way is probably doing the obvious thing. I think that is the more appropriate takeaway from PEP 20.

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12 comments · 6 top-level

xigoi4y ago· 4 in thread

I can think of at least 2 obvious ways to iterate through something: for loops and comprehensions.

voltagedivider4y ago

You're right that both iterate through something but `for` loops and comprehensions aren't used as if they were interchangeable.

For example, you'll sometimes see people do bad stuff like this:

  >>> lst = []
  >>> 
  >>> [lst.append(i + i) for i in range(10)]
  [None, None, None, None, None, None, None, None, None, None]
  >>> 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

When they should be doing this:

  >>> lst = []
  >>> 
  >>> for i in range(10):
  ...     lst.append(i + i)
  ... 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

Or just this:

  >>> lst = [i + i for i in range(10)]
  >>> 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

jstx14y ago

The first append version will more often be in a loop. It's unlikely that someone will know enough to use comprehensions but not enough to still use append.

1 more reply

a_t484y ago

    lst = [range(0, 10, 2)]

1 more reply

dragonwriter4y ago

To generate a list/dictionary/geneator from an input iterable, you use a comprehension of the appropriate type.

To iterate through it without doing one of those things, you use a for loop.

In “one obvious way to do it”, “it” refers to a concrete task; the same is not necessarily intended to be true of arbitrarily broad generalizations of classes of tasks.

dragonwriter4y ago· 1 in thread

> the author used two different ways of hyphenating

No, first, it doesn't use hyphenating at all, it uses hyphens as an ASCII approximation for typographical dashes used to set off a phrase (a distinct function from hyphenation), and, second, in that quote they used one way of doing it: “two dashes set closed on the side of the main sentence and set open on the side of set-off phrase”.

It is an unusual way of doing it—just as with actual typographical dashes, setting open or closed symmetrically would be more common—but it's not two ways.

EDIT: And the third use (in the heading and later in the body) is seperating parts where neither is a mid-sentence appositive phrase, and uses open-on-both sides. So that's not a different way of doing the same thing, it's a different way of doing a semantically different thing.

Actually, I think the dash use makes a good illustration of how the “it” in “one way to do it” is intended.

Wowfunhappy4y ago

> “two dashes set closed on the side of the main sentence and set open on the side of set-off phrase”.

Eh, I don't think that's the interpretation the author was going for. The author wanted to show two different ways of approximating a dash, and he had limited options.

If he'd done this-- for example-- he would have been showing one way, not two.

If he'd done this --for example-- you would have called it "two dashes set open on the side of the main sentence and set closed on the side of set-off phrase".

If he'd done this-- for example -- it would have been too obvious (on the same line).

I suppose he could have done this-- for example--but I still think that would have been too obvious. You're not supposed to see it on a first read.

> And the third use (in the heading and later in the body) is seperating parts where neither is a mid-sentence appositive phrase, and uses open-on-both sides. So that's not a different way of doing the same thing, it's a different way of doing a semantically different thing.

It's a different use of a dash, but it's still a place where you'd typically use a dash.

-----

Edit: You know what, thinking about it again—perhaps both interpretations are valid. That almost adds to the effectiveness of the whole thing.

bilalq4y ago· 1 in thread

It's not even obvious how to run Python or dependencies in the first place. Even putting aside the 2.7/3.x fiasco (that still causes problems even today), you're left with figuring out wheel vs egg vs easy-install vs setuptools vs poetry vs pip vs pip3 vs pip3.7 vs pip3.8 vs piptools vs conda vs anaconda vs miniconda vs virtualenv vs pyenv vs pipenv vs pyflow.

dylan6044y ago

it's like you read my mind.

jstx14y ago

> And the philosophy here still applies: when you read anyone else's python code, the obvious way is probably doing the obvious thing.

I don't get what you mean by this.

When I read someone else's code, what is obvious to me isn't necessarily what was obvious to the author. For an illustration of this, have a look at the day 1 solution thread from this year's Advent of Code - https://www.reddit.com/r/adventofcode/comments/r66vow/2021_d... (you can search for Python solutions) - and see how many different ways there are to solve a fairly straightforward problem.

JasonFruit4y ago

I suspect this comment was an elaborate nerdsnipe.

srcreigh4y ago

The author uses "only one" to clarify "one". So obviously "one" means at least one.

    There should be at least one-- preferably only one --obvious way to do it.

Kinda funny meta joke considering everybody conflates "one" and "only one" to mean the same thing. Preferably there would only be one obvious way to describe "one". :p

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12 comments · 6 top-level

xigoi4y ago· 4 in thread

I can think of at least 2 obvious ways to iterate through something: for loops and comprehensions.

voltagedivider4y ago

You're right that both iterate through something but `for` loops and comprehensions aren't used as if they were interchangeable.

For example, you'll sometimes see people do bad stuff like this:

  >>> lst = []
  >>> 
  >>> [lst.append(i + i) for i in range(10)]
  [None, None, None, None, None, None, None, None, None, None]
  >>> 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

When they should be doing this:

  >>> lst = []
  >>> 
  >>> for i in range(10):
  ...     lst.append(i + i)
  ... 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

Or just this:

  >>> lst = [i + i for i in range(10)]
  >>> 
  >>> lst
  [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
  >>>

jstx14y ago

The first append version will more often be in a loop. It's unlikely that someone will know enough to use comprehensions but not enough to still use append.

1 more reply

a_t484y ago

    lst = [range(0, 10, 2)]

1 more reply

dragonwriter4y ago

To generate a list/dictionary/geneator from an input iterable, you use a comprehension of the appropriate type.

To iterate through it without doing one of those things, you use a for loop.

In “one obvious way to do it”, “it” refers to a concrete task; the same is not necessarily intended to be true of arbitrarily broad generalizations of classes of tasks.

dragonwriter4y ago· 1 in thread

> the author used two different ways of hyphenating

It is an unusual way of doing it—just as with actual typographical dashes, setting open or closed symmetrically would be more common—but it's not two ways.

Actually, I think the dash use makes a good illustration of how the “it” in “one way to do it” is intended.

Wowfunhappy4y ago

> “two dashes set closed on the side of the main sentence and set open on the side of set-off phrase”.

Eh, I don't think that's the interpretation the author was going for. The author wanted to show two different ways of approximating a dash, and he had limited options.

If he'd done this-- for example-- he would have been showing one way, not two.

If he'd done this --for example-- you would have called it "two dashes set open on the side of the main sentence and set closed on the side of set-off phrase".

If he'd done this-- for example -- it would have been too obvious (on the same line).

I suppose he could have done this-- for example--but I still think that would have been too obvious. You're not supposed to see it on a first read.

It's a different use of a dash, but it's still a place where you'd typically use a dash.

-----

Edit: You know what, thinking about it again—perhaps both interpretations are valid. That almost adds to the effectiveness of the whole thing.

bilalq4y ago· 1 in thread

dylan6044y ago

it's like you read my mind.

jstx14y ago

> And the philosophy here still applies: when you read anyone else's python code, the obvious way is probably doing the obvious thing.

I don't get what you mean by this.

JasonFruit4y ago

I suspect this comment was an elaborate nerdsnipe.

srcreigh4y ago

The author uses "only one" to clarify "one". So obviously "one" means at least one.

    There should be at least one-- preferably only one --obvious way to do it.

Kinda funny meta joke considering everybody conflates "one" and "only one" to mean the same thing. Preferably there would only be one obvious way to describe "one". :p

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