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Count(*) vs Count(1) - SQL Server
...ution-time work. The Compilation time work is a trivially small amount of extra work in the current implementation. There is an expansion of the * to all columns in some cases followed by a reduction back to 1 column being output due to how some of the internal operations work in binding and optim...
Counting array elements in Python [duplicate]
... the number of elements in an array, because contrary to logic array.count(string) does not count all the elements in the array, it just searches for the number of occurrences of string.
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Convert two lists into a dictionary
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dict([(k, v) for k, v in zip(keys, values)])
In the first two cases, an extra layer of non-operative (thus unnecessary) computation is placed over the zip iterable, and in the case of the list comprehension, an extra list is unnecessarily created. I would expect all of them to be less performant,...
Are loops really faster in reverse?
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i-- is as fast as i++
This code below is as fast as yours, but uses an extra variable:
var up = Things.length;
for (var i = 0; i < up; i++) {
Things[i]
};
The recommendation is to NOT evaluate the size of the array each time. For big arrays one can see the performance degradation.
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Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc
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Aha so by using * you are adding extra work for the DB. Ok that's one reason I hadn't thought of.
– Ankur
Jun 4 '10 at 6:50
1
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Unable to find a locale path to store translations for file __init__.py
I'm trying to translate a Django app. I created some strings with {% trans %} in my templates. However, when I execute the following command in my app folder, I receive an error message:
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How to decide font color in white or black depending on background color?
...Color, darkColor) {
var color = (bgColor.charAt(0) === '#') ? bgColor.substring(1, 7) : bgColor;
var r = parseInt(color.substring(0, 2), 16); // hexToR
var g = parseInt(color.substring(2, 4), 16); // hexToG
var b = parseInt(color.substring(4, 6), 16); // hexToB
return (((r * 0.299) + (g * ...
How to loop backwards in python? [duplicate]
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All of these three solutions give the same results if the input is a string:
1.
def reverse(text):
result = ""
for i in range(len(text),0,-1):
result += text[i-1]
return (result)
2.
text[::-1]
3.
"".join(reversed(text))
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Difference between JSON.stringify and JSON.parse
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JSON.stringify turns a JavaScript object into JSON text and stores that JSON text in a string, eg:
var my_object = { key_1: "some text", key_2: true, key_3: 5 };
var object_as_string = JSON.stringify(my_object);
// "{"key_1":"...
Regex Pattern to Match, Excluding when… / Except between
...alizes the context you want to ignore by replacing potentially conflicting strings. If you only want to match, then you can replace with an empty string, then run your match in the second step. If you want to replace, you can first replace the strings to be ignored with something distinctive, for in...