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What does && mean in void *p = &&abc;
... that address points to a instruction within the .text section of the executable. The .text section is the one which holds you program's (binary) code to be executed.
You can inspect this with:
objdump -x a.out
A practical example
As described in GCC, you can use this to initialize a jump table. S...
How to prevent gcc optimizing some statements in C?
In order to make a page dirty (switching on the dirty bit in the page table entry), I touch the first bytes of the page like this:
...
Pandas every nth row
...2nd row it would be df.iloc[1::5, :].
– Little Bobby Tables
Nov 13 '16 at 17:18
17
You can omit t...
Differences in boolean operators: & vs && and | vs ||
...ou're talking about the logical meaning of both operators, here you have a table-resume:
boolean a, b;
Operation Meaning Note
--------- ------- ----
a && b logical AND short-circuiting
a || b logical OR ...
How to write a JSON file in C#?
...
@RobertHarvey Liam's Json.Net link has a nice table showing what the differences are. Coming from the people that make it, of course you should take it with a grain of salt, but it is indeed better than the built-in things.
– Tim S.
...
PHP Error handling: die() Vs trigger_error() Vs throw Exception
...ry {
while ($row = gather_data()) {
$db->query('INSERT INTO `table` (`foo`,`bar`) VALUES(?,?)', ...);
}
$db->query('COMMIT');
} catch(Exception $e) {
$db->query('ROLLBACK');
}
Here, if gather_data() just plain croaked (using E_USER_ERROR or die()) there's a chance, ...
Flask-SQLAlchemy import/context issue
... id = db.Column(db.Integer, primary_key=True)
...
# Create the database tables.
db.create_all()
...
# start the flask loop
app.run()
I just splitted one app.py to app.py and model.py without using Blueprint. In that case, the above answer dosen't work. A line code is needed to work.
before:
...
How do I get the current time zone of MySQL?
...alues are not stored with timezone information in MySQL:
mysql> create table foo (tstamp datetime) Engine=MyISAM;
Query OK, 0 rows affected (0.06 sec)
mysql> insert into foo (tstamp) values (now());
Query OK, 1 row affected (0.00 sec)
mysql> set time_zone = '+01:00';
Query OK, 0 rows aff...
Select data from date range between two dates
I have a table Named Product_Sales and it holds data like this
19 Answers
19
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Python “SyntaxError: Non-ASCII character '\xe2' in file”
...
For folks hunting down the problem character, this table is useful. Everything in the "UTF-8 Bytes" column which starts with %E2 is a candidate. Generally the issue is editing code with "smart" features turned on like "smart quotes" replacing " with “ (U+201C) and ” (U+20...