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What exactly is a reentrant function?
...rant?
No.
For example, let's have a C++ function that takes both a lock, and a callback as a parameter:
#include <mutex>
typedef void (*callback)();
std::mutex m;
void foo(callback f)
{
m.lock();
// use the resource protected by the mutex
if (f) {
f();
}
// u...
TypeError: 'dict_keys' object does not support indexing
...
Convert an iterable to a list may have a cost. Instead, to get the the first item, you can use:
next(iter(keys))
Or, if you want to iterate over all items, you can use:
items = iter(keys)
while True:
try:
item...
Set Django IntegerField by choices=… name
...bject. Hard to find with Google too so thanks.
– Alexander Ljungberg
Jul 13 '09 at 13:54
1
FWIW, ...
How to write log base(2) in c/c++
... log2 (x) = logy (x) / logy (2)
where y can be anything, which for standard log functions is either 10 or e.
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Transpose/Unzip Function (inverse of zip)?
I have a list of 2-item tuples and I'd like to convert them to 2 lists where the first contains the first item in each tuple and the second list holds the second item.
...
Media Queries: How to target desktop, tablet, and mobile?
...1281px) { /* hi-res laptops and desktops */ }
In practice, many designers convert pixels to ems, largely because ems afford better zooming. At standard zoom 1em === 16px, multiply pixels by 1em/16px to get ems. For example, 320px === 20em.
In response to the comment, min-width is standard in "mobil...
String contains - ignore case [duplicate]
...ks if CharSequence contains a search CharSequence irrespective of
case, handling null. Case-insensitivity is defined as by
String.equalsIgnoreCase(String).
A null CharSequence will return false.
This one will be better than regex as regex is always expensive in terms of performance.
For ...
What is Hindley-Milner?
I encountered this term Hindley-Milner , and I'm not sure if grasp what it means.
3 Answers
...
Properly escape a double quote in CSV
...
I know this is an old post, but here's how I solved it (along with converting null values to empty string) in C# using an extension method.
Create a static class with something like the following:
/// <summary>
/// Wraps value in quotes if necessary and converts nulls to empt...
MySQL SELECT WHERE datetime matches day (and not necessarily time)
...ults when using BETWEEN with date or time values, use CAST() to explicitly convert the values to the desired data type. Examples: If you compare a DATETIME to two DATE values, convert the DATE values to DATETIME values. If you use a string constant such as '2001-1-1' in a comparison to a DATE, cast ...