On 9/29/2019 9:45 AM, Eryk Sun wrote:
On 9/29/19, Anthony Flury via Python-list wrote:
Using python 3.6 building a tuple like this :
my_tuple = tuple([x*x for x in range(1,1000)])
The list comprehension is implemented internally as a function that
builds and returns the list. This function
On 9/29/19, Anthony Flury via Python-list wrote:
>
> Using python 3.6 building a tuple like this :
>
> my_tuple = tuple([x*x for x in range(1,1000)])
The list comprehension is implemented internally as a function that
builds and returns the list. This function creates an empty list and
loops over
I have just noticed an oddity :
Using python 3.6 building a tuple like this :
my_tuple = tuple([x*x for x in range(1,1000)])
is about 1/3 quicker than
my_tuple = tuple(x*x for x in range(1,1000))
Measurements :
$ python3 -m timeit 'my_tuple = tuple([x*x for x in range(1,1000)])'
1
George: apologies for mis-identifying yourself as OP.
Israel:
On 22/02/19 6:04 AM, Israel Brewster wrote:
Actually not a ’toy example’ at all. It is simply the first step in
gridding some data I am working with - a problem that is solved by tools
like SatPy, but unfortunately I can’t use SatPy
Actually not a ’toy example’ at all. It is simply the first step in gridding
some data I am working with - a problem that is solved by tools like SatPy, but
unfortunately I can’t use SatPy because it doesn’t recognize my file format,
and you can’t load data directly. Writing a custom file import
I don't know whether this is a toy example, having grid of this size is not
uncommon. True, it would make more sense to do distribute more work on each
box, if there was any. One has to find a proper balance, as with many other
things in life. I simply responded to a question by the OP.
George
O
George
On 21/02/19 1:15 PM, george trojan wrote:
def create_box(x_y):
return geometry.box(x_y[0] - 1, x_y[1], x_y[0], x_y[1] - 1)
x_range = range(1, 1001)
y_range = range(1, 801)
x_y_range = list(itertools.product(x_range, y_range))
grid = list(map(create_box, x_y_range))
Which creates
def create_box(x_y):
return geometry.box(x_y[0] - 1, x_y[1], x_y[0], x_y[1] - 1)
x_range = range(1, 1001)
y_range = range(1, 801)
x_y_range = list(itertools.product(x_range, y_range))
grid = list(map(create_box, x_y_range))
Which creates and populates an 800x1000 “grid” (represented as a fl
> On Feb 18, 2019, at 6:37 PM, Ben Finney wrote:
>
> I don't have anything to add regarding your experiments with
> multiprocessing, but:
>
> Israel Brewster writes:
>
>> Which creates and populates an 800x1000 “grid” (represented as a flat
>> list at this point) of “boxes”, where a box is a
I don't have anything to add regarding your experiments with
multiprocessing, but:
Israel Brewster writes:
> Which creates and populates an 800x1000 “grid” (represented as a flat
> list at this point) of “boxes”, where a box is a
> shapely.geometry.box(). This takes about 10 seconds to run.
Thi
I have the following code running in python 3.7:
def create_box(x_y):
return geometry.box(x_y[0] - 1, x_y[1], x_y[0], x_y[1] - 1)
x_range = range(1, 1001)
y_range = range(1, 801)
x_y_range = list(itertools.product(x_range, y_range))
grid = list(map(create_box, x_y_range))
Which creates and
On Dec 4, 1:28 pm, alex23 <[EMAIL PROTECTED]> wrote:
> On Dec 4, 8:12 pm, [EMAIL PROTECTED] wrote:
>
> > About the piece of code you posted, there is something I don't
> > understand.
>
> > for i, line in data:
>
> > where data is a file object. Is it legal to write that?
> > I believe it r
On Dec 4, 8:12 pm, [EMAIL PROTECTED] wrote:
> About the piece of code you posted, there is something I don't
> understand.
>
> for i, line in data:
>
> where data is a file object. Is it legal to write that?
> I believe it results in "too many values to unpack" or do I miss
> something?
>F
About the piece of code you posted, there is something I don't
understand.
for i, line in data:
where data is a file object. Is it legal to write that?
I believe it results in "too many values to unpack" or do I miss
something?
/Ben
On Dec 4, 10:26 am, [EMAIL PROTECTED] wrote:
> Matt, r
Matt, really thanks for your comments!
Even thogh it was not a direct answer to my questions,
I like your coding style very much and I think you have a good point.
About the number of line in the file, because I get that info from
another
in advance. Therefore I thought it could be hard coded.
BT
Thanks for your questions. Here come some answer below.
On Dec 2, 2:50 pm, Steven D'Aprano <[EMAIL PROTECTED]
cybersource.com.au> wrote:
> On Tue, 02 Dec 2008 03:41:29 -0800,bkamraniwrote:
> > Hi Python gurus!
> > I'm going to read in an Ascii file containing float numbers in rows and
> > columns
On Dec 2, 3:51 am, [EMAIL PROTECTED] wrote:
> I forgot to mention that I did a simple timeit test which doesn't
> show
> significant runtime difference 3.5 sec for dictionary case and 3.48
> for
> list case.
>
> def read_as_dictionary():
> fil = open('myDataFile', 'r')
> forces = {}
> f
On Tue, 02 Dec 2008 03:41:29 -0800, bkamrani wrote:
> Hi Python gurus!
> I'm going to read in an Ascii file containing float numbers in rows and
> columns (say 10 columns 50 rows) for further numerical process.
> Which format is best to save them in, eg, dictionary, list, or numpy
> array when
I forgot to mention that I did a simple timeit test which doesn't
show
significant runtime difference 3.5 sec for dictionary case and 3.48
for
list case.
def read_as_dictionary():
fil = open('myDataFile', 'r')
forces = {}
for region in range(25):
forces[region] = {}
for s
Hi Python gurus!
I'm going to read in an Ascii file containing float numbers in rows
and columns (say 10 columns 50 rows) for further numerical
process. Which format is best to save them in, eg, dictionary, list,
or numpy array when it comes to performance?
Will it be beneficial to convert all
B wrote:
>
> # pass in window handle and parent node
> def gwl(node, hwnd):
> if hwnd:
> yield node, hwnd
> for nd, wnd in Wnd.gwl(node.children[-1], GetWindow(hwnd,
> GW_CHILD)):
> yield nd, wnd
> for nd, wnd in Wnd.gwl(node, GetWind
B wrote:
Now it works, but it runs quite slow (compared to the c++ app). I
changed gwl from strait recursion to use a generator and that helped,
but it still takes 0.5-1.0 seconds to populate the tree. What I'm
wondering is am I doing it in a really inefficient way, or is it just
python?
W
Hey I found some (VERY) old C++ code of mine that recursively built a
tree of the desktop window handles (on windows) using: (they are stored
in an STL vector)
void FWL(HWND hwnd, int nFlag) // Recursive Function
{
hwnd = GetWindow(hwnd, nFlag);
if(hwnd == NULL)
cjl wrote:
> Group:
>
> I'm new to python and new to mysql.
>
> I have a csv file that is about 200,000 rows that I want to add to a
> mysql database. Yes, I know that I can do this directly from the
> mysql command line, but I am doing it through a python script so that
> I can munge the data b
On May 20, 5:55 pm, cjl <[EMAIL PROTECTED]> wrote:
...snip...
> conn = MySQLdb.connect(db="database", host="localhost", user="root",
> passwd="password")
> c = conn.cursor()
>
> reader = csv.reader(open(sys.argv[1]))
> for row in reader:
> data1, data2, data3, data4 = row
> data = (data1,da
Group:
I'm new to python and new to mysql.
I have a csv file that is about 200,000 rows that I want to add to a
mysql database. Yes, I know that I can do this directly from the
mysql command line, but I am doing it through a python script so that
I can munge the data before adding it.
I have th
[Eric Texier]
> I need speed here. What will be the fastest method or does it matter?
Follow Alex's advice and use the timeit module, but do not generalize
from too small examples; otherwise, the relative timings will be
thrown-off by issues like the time to lookup "write" and "a" and "str"
(all of
Eric Texier <[EMAIL PROTECTED]> wrote:
> I need speed here. What will be the fastest method or does it matter?
>
> (for the example 'a' is only 3 values for the clarity of the example)
> a = [1,3,4.] ##
>
>
> method1:
>
> f.write("vec %f %f %f \n" % (a[0],a[1],a[2]))
>
> method2:
>
> f.write
I need speed here. What will be the fastest method or does it matter?
(for the example 'a' is only 3 values for the clarity of the example)
a = [1,3,4.] ##
method1:
f.write("vec %f %f %f \n" % (a[0],a[1],a[2]))
method2:
f.write("vec " + str(a[0]) + " " + str(a[1]) + " " + str(a[2]) + "\n")
a
reinsn wrote:
> Hi,
>
> I have got a specific question on performance: Is the overhead of
> object creation in Python lower than in Java? I mean, I would argue, in
> Java by object creation, the complete class is the model and all
> methods and attributes are generated for the object.
> In Python
Hi,
I have got a specific question on performance: Is the overhead of
object creation in Python lower than in Java? I mean, I would argue, in
Java by object creation, the complete class is the model and all
methods and attributes are generated for the object.
In Python, methods and objects are onl
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