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Best way to handle list.index(might-not-exist) in python?
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edited Jan 25 '10 at 14:32
answered Jan 25 '10 at 14:02
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How do I create a file AND any folders, if the folders don't exist?
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answered Jul 8 '10 at 7:56
Christopher B. AdkinsChristopher B. Adkins
3,22322 gold badges2222 silver badges2727 bronze badges
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Why does `a == b or c or d` always evaluate to True?
...gt; ast.parse("if a == b or c or d or e: ...")
<_ast.Module object at 0x1031ae6a0>
>>> ast.dump(_)
"Module(body=[If(test=BoolOp(op=Or(), values=[Compare(left=Name(id='a', ctx=Load()), ops=[Eq()], comparators=[Name(id='b', ctx=Load())]), Name(id='c', ctx=Load()), Name(id='d', ctx=Load(...
Apply a function to every row of a matrix or a data frame
... 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extra arguments to the function as fourth, fifth, ... arguments to apply().
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How to redirect output to a file and stdout
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10 Answers
10
Active
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How can I check if an ip is in a network in Python?
...t == net
address = dottedQuadToNum("192.168.1.1")
networka = networkMask("10.0.0.0",24)
networkb = networkMask("192.168.0.0",24)
print (address,networka,networkb)
print addressInNetwork(address,networka)
print addressInNetwork(address,networkb)
This outputs:
False
True
If you just want a singl...
“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
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1003
I would recommend using INSERT...ON DUPLICATE KEY UPDATE.
If you use INSERT IGNORE, then the...
What are deferred objects?
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101
Deferred Object
As of jQuery 1.5, the Deferred object provides a way to register multiple call...
Reference — What does this symbol mean in PHP?
..., then the increment/decrement operation is done.
For example:
$apples = 10;
for ($i = 0; $i < 10; ++$i) {
echo 'I have ' . $apples-- . " apples. I just ate one.\n";
}
Live example
In the case above ++$i is used, since it is faster. $i++ would have the same results.
Pre-increment is a l...
XPath to find elements that does not have an id or class
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answered Mar 8 '10 at 19:36
WelbogWelbog
54.1k88 gold badges101101 silver badges118118 bronze badges
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