how best to split into singleton and sequence

>>> l = []
>>> s = 'a|b'
>>> t, l = s.split('|')
>>> t
'a'
>>> l
'b'
>>> s = 'a|b|c|d'
>>> t, l = s.split('|')
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: too many values to unpack
>>>

so, i imagine what is happening is the lhs, t,l, is really
(t, (l)), i.e. only two items.

so how should i have done this readably and simply?

randy

Randy Bush

"Randy Bush" <> wrote:

> >>> l = []
> >>> s = 'a|b'
> >>> t, l = s.split('|')
> >>> t
> 'a'
> >>> l
> 'b'
> >>> s = 'a|b|c|d'
> >>> t, l = s.split('|')
> Traceback (most recent call last):
> File "<stdin>", line 1, in ?
> ValueError: too many values to unpack
> >>>
>
> so, i imagine what is happening is the lhs, t,l, is really
> (t, (l)), i.e. only two items.
>
> so how should i have done this readably and simply?

>>> s = 'a|b|c|d'
>>> l = s.split('|')
>>> t = l.pop(0)

By the way, don't use 'l' as an identifier; it is very close to '1' visually.

George

George Sakkis

Randy Bush wrote:

> so, i imagine what is happening is the lhs, t,l, is really
> (t, (l)), i.e. only two items.
>
> so how should i have done this readably and simply?

Your question isn't at all clear. You're trying to assign a 4-element
tuple to two elements. That generates a ValueError.

Did you want to only split once at most? Then it's s.split('|', 1).
Did you want to assign the first element to the first variable and the
rest to the next? Then it's x = s.split('|'); a, b = x[0], x[1:].

--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
It's funny when you think about it / How coincidence rules
-- Anggun

Erik Max Francis

what you wrote is the most readable to me:

just asign the first 2 element to t, l respectively and forget about
the rest. I assume that is what you want. I think perl may do it this
way.

A solution which I think looks uglier is :

t, l = s.split('|')[:2]

Randy Bush wrote:
> >>> l = []
> >>> s = 'a|b'
> >>> t, l = s.split('|')
> >>> t
> 'a'
> >>> l
> 'b'
> >>> s = 'a|b|c|d'
> >>> t, l = s.split('|')
> Traceback (most recent call last):
> File "<stdin>", line 1, in ?
> ValueError: too many values to unpack
> >>>
>
> so, i imagine what is happening is the lhs, t,l, is really
> (t, (l)), i.e. only two items.
>
> so how should i have done this readably and simply?
>
> randy

bonono@gmail.com