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How to check if a file is a valid image file?
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A lot of times the first couple chars will be a magic number for various file formats. You could check for this in addition to your exception checking above.
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How to get the caret column (not pixels) position in a textarea, in characters, from the start?
...refox, Safari (and other Gecko based browsers) you can easily use textarea.selectionStart, but for IE that doesn't work, so you will have to do something like this:
function getCaret(node) {
if (node.selectionStart) {
return node.selectionStart;
} else if (!document.selection) {
return ...
If using maven, usually you put log4j.properties under java or resources?
... configuration: Run->Run Configurations...->Java Application->New select the Classpath tab, select Advanced and browse to your src/resources directory.
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Row count with PDO
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$sql = "SELECT count(*) FROM `table` WHERE foo = ?";
$result = $con->prepare($sql);
$result->execute([$bar]);
$number_of_rows = $result->fetchColumn();
Not the most elegant way to do it, plus it involves an extra query...
How do I find numeric columns in Pandas?
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You could use select_dtypes method of DataFrame. It includes two parameters include and exclude. So isNumeric would look like:
numerics = ['int16', 'int32', 'int64', 'float16', 'float32', 'float64']
newdf = df.select_dtypes(include=numer...
Visual Studio : short cut Key : Duplicate Line
...ure is now built-in in VS2017: Ctrl + E, V duplicates a line if nothing is selected, or duplicates selection. You can assign it to a different key combination, or find it in the menu:
See this reference for more information.
Pre VS2017, built-in method using clipboard
As @cand mentioned, you ca...
What is the purpose of Order By 1 in SQL select statement?
...number stands for the column based on the number of columns defined in the SELECT clause. In the query you provided, it means:
ORDER BY A.PAYMENT_DATE
It's not a recommended practice, because:
It's not obvious/explicit
If the column order changes, the query is still valid so you risk ordering ...
What is the precise meaning of “ours” and “theirs” in git?
...ics:
Merges:
$ git checkout master
$ git merge feature
If you want to select the version in master:
$ git checkout --ours codefile.js
If you want to select the version in feature:
$ git checkout --theirs codefile.js
Rebases:
$ git checkout feature
$ git rebase master
If you want to s...
Generating random numbers in Objective-C
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arc4random_stir(void);
void
arc4random_addrandom(unsigned char *dat, int datlen);
DESCRIPTION
The arc4random() function uses the key stream generator employed by the arc4 cipher, which uses 8*8 8
bit S-Boxes. The S-Boxes can be in about (2**1700) states. The arc4random(...
Generate random int value from 3 to 6
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This generates a random number between 0-9
SELECT ABS(CHECKSUM(NEWID()) % 10)
1 through 6
SELECT ABS(CHECKSUM(NEWID()) % 6) + 1
3 through 6
SELECT ABS(CHECKSUM(NEWID()) % 4) + 3
Dynamic (Based on Eilert Hjelmeseths Comment)
SELECT ABS(CHECKSUM(NEWID()) % (@ma...