On Tue, Oct 16, 2012 at 10:13 PM, Dave Angel <(E-Mail Removed)> wrote:

> On 10/16/2012 09:54 PM, Kevin Anthony wrote:

>> I've been teaching myself list comprehension, and i've run across something

>> i'm not able to convert.

>>

>> here's the original code for matrix multiplcation

>>

>> retmatrix = Matrix(self.__row,other.__col)

>> for m in range(0,retmatrix.__row):

>> for n in range(0,retmatrix.__col):

>> product = 0

>> for p in range(1,self.__col+1):

>> product += (self.__matrix[m][p] * other.__matrix[p][n])

>> retmatrix.__matrix[m][n] = product

>>

>> Here is what i have so far:

>> retmatrix.__matrix = [[ product = product + (self.__matrix[m][p]*

>> other.__matrix[p][n])

>> if product else self.__matrix[m][p]* other.__matrix[p][n])

>> for p in range(0,self.col)

>> for n in range(0,self.col)]

>> for m in range(0,self.__row)]

>>

>> But i know that isn't correct, can someone nudge my in the right direction?

>>

>>

>

> The biggest thing to learn about list comprehensions is when not to use

> them. I can't imagine how your latter version (even if correct) is

> clearer than the first.
I think he might be using the wrong function for a matrix

multiplication, not that it's not workable, but there are other

libraries like numpy that could help out.

I wouldn't use list comprehension for this, unless it might be several

lists that interact.

>

>

>

> --

>

> DaveA

>

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