multiply utple or list

[Jim Red]

what is the best way to multiply a tuple or list by a given value

exp.
multiply (4, 5) by 2 => (8, 10)

cheers

jr

 

[Karl Scalet]

what is the best way to multiply a tuple or list by a given value

exp.
multiply (4, 5) by 2 => (8, 10)

cheers

jr
i.e.:

>>> import operator
>>> [ operator.mul(x,2) for x in (4,5)]

regards,
Karl

 

[P]

what is the best way to multiply a tuple or list by a given value

exp.
multiply (4, 5) by 2 => (8, 10)

something like this?

import types
def multiply_sequence(sequence, multiplier):
new_sequence = map(lambda item: item*multiplier, sequence)
if type(sequence) == types.TupleType:
return tuple(new_sequence)
elif type(sequence) == types.ListType:
return new_sequence

 

[Diez B. Roggisch]

import operator

[ operator.mul(x,2) for x in (4,5)]

Why not simply * ?

[ x * 2 for x in (4,5)]

And you might surround it by tuple to gain a tuple

tuple([ x * 2 for x in (4,5)])

Another way would be to use Numeric

import Numeric
a = Numeric.array((10,2), Numeric.Float32)
a = a * 2

 

[Karl Scalet]

import operator
[ operator.mul(x,2) for x in (4,5)]

Why not simply * ?

[ x * 2 for x in (4,5)]

oops, of course. I had the map function in mind,
which only accepts a function, but this would come
to something like:

li=(4,5)
map(operator.mul, li, (2,)*len(li))

and is certainly worse then list comprehension

regards,
Karl