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Are tuples more efficient than lists in Python?
...external array of pointers.
This gives tuples a small speed advantage for indexed lookups and unpacking:
$ python3.6 -m timeit -s 'a = (10, 20, 30)' 'a[1]'
10000000 loops, best of 3: 0.0304 usec per loop
$ python3.6 -m timeit -s 'a = [10, 20, 30]' 'a[1]'
10000000 loops, best of 3: 0.0309 usec per ...
Take a screenshot of a webpage with JavaScript?
...Width, wb.Height));
wb.Dispose();
return bitmap;
}
And then via PHP you can do:
exec("CreateScreenShot.exe -url http://.... -save C:/shots domain_page.png");
Then you have the screenshot in the server side.
shar...
How to implement a unique index on two columns in rails
I have a table and I'm trying to add a unique index on two columns. Those columns are also indexed. So my question is if I just can remove the indexes who were just for one column or if I have to use all three indexes:
...
Creating a ZIP Archive in Memory Using System.IO.Compression
...
Working solution for MVC
public ActionResult Index()
{
string fileName = "test.pdf";
string fileName1 = "test.vsix";
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";
byte[] fileBytes = System.IO.File...
Explain the use of a bit vector for determining if all characters are unique
...bits (flag). Each bit in your code states whether the character with bit's index was found in string or not. You could use bit vector for the same reason instead of int. There are two differences between them:
Size. int has fixed size, usually 4 bytes which means 8*4=32 bits (flags). Bit vector us...
Using socket.io in Express 4 and express-generator's /bin/www
...by defining module.exports as a function which accepts io as a parameter.
index.js
module.exports = function(io) {
var app = require('express');
var router = app.Router();
io.on('connection', function(socket) {
(...)
});
return router;
}
Then, pass io into the mod...
MySQL order by before group by
...
For scaling, the compound INDEX(post_author, post_date) is important.
– Rick James
Mar 1 '15 at 16:08
1
...
Total memory used by Python process?
...# non-Linux?
# get VmKey line e.g. 'VmRSS: 9999 kB\n ...'
i = v.index(VmKey)
v = v[i:].split(None, 3) # whitespace
if len(v) < 3:
return 0.0 # invalid format?
# convert Vm value to bytes
return float(v[1]) * _scale[v[2]]
def memory(since=0.0):
'''Return...
Algorithm to return all combinations of k elements from n
...hm 382: Combinations of M out of N Objects' (1970)
The algorithm in C...
Index of Combinations in Lexicographical Order (Buckles Algorithm 515)
You can also reference a combination by its index (in lexicographical order). Realizing that the index should be some amount of change from right to lef...
FileNotFoundException while getting the InputStream object from HttpURLConnection
...ck a response in form of xml string. The app is hosted on apache-tomcat locally.
7 Answers
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