On 1/2/2011 9:43 AM gervaz said...
On 31 Dic 2010, 16:43, Emile van Sebille<em...@fenx.com> wrote:
On 12/31/2010 7:22 AM gervaz said...
Hi all, I would like to ask you how I can use the more efficient join
operation in a code like this:
class Test:
... def __init__(self, v1, v2):
... self.v1 = v1
... self.v2 = v2
...
def prg(l):
... txt = ""
... for x in l:
... if x.v1 is not None:
... txt += x.v1 + "\n"
... if x.v2 is not None:
... txt += x.v2 + "\n"
... return txt
...
t1 = Test("hello", None)
t2 = Test(None, "ciao")
t3 = Test("salut", "hallo")
t = [t1, t2, t3]
prg(t)
'hello\nciao\nsalut\nhallo\n'
The idea would be create a new list with the values not None and then
use the join function... but I don't know if it is really worth it.
Any hint?
def prg2(l):
return "\n".join([x for x in l if x])
Emile
... e = []
... for x in l:
... if x.v1 is not None:
... e.append(x.v1)
... if x.v2 is not None:
... e.append(x.v2)
... return "\n".join(e)
...
prg2(t)
'hello\nciao\nsalut\nhallo'
Thanks, Mattia- Nascondi testo citato
- Mostra testo citato -- Nascondi testo citato
- Mostra testo citato -
Sorry, but it does not work
Oh -- you want a working solution, not a hint? OK.
class Test:
def __init__(self, v1, v2):
self.v1 = v1
self.v2 = v2
t1 = Test("hello", None)
t2 = Test(None, "ciao")
t3 = Test("salut", "hallo")
t = [t1, t2, t3]
"\n".join([y for x in t for y in [x.v1,x.v2] if y])
Emile
def prg3(l):
... return "\n".join([x for x in l if x])
...
prg3(t)
Traceback (most recent call last):
File "<stdin>", line 1, in<module>
File "<stdin>", line 2, in prg3
TypeError: sequence item 0: expected str instance, Test found
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