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When saving, how can you check if a field has changed?
...
Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
Concurrent HashSet in .NET Framework?
...ass.
private ConcurrentBag<string> _data;
Self-implementation
Finally, as you did, you can implement your own data type, using lock or other ways that the .NET provides you to be thread-safe. Here is a great example: How to implement ConcurrentHashSet in .Net
The only drawback of this sol...
Circular (or cyclic) imports in Python
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There was a really good discussion on this over at comp.lang.python last year. It answers your question pretty thoroughly.
Imports are pretty straightforward really. Just remember the following:
'import' and 'from xxx import yyy' ...
How to post data in PHP using file_get_contents?
...Sending an HTTP POST request using file_get_contents is not that hard, actually : as you guessed, you have to use the $context parameter.
There's an example given in the PHP manual, at this page : HTTP context options (quoting) :
$postdata = http_build_query(
array(
'var1' => 'some...
Could not reserve enough space for object heap
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Anyone found a solution that actually work 100% of the time? This solution solves the problem temporarily but then suddenly it comes back. I've got 16GB ram and I'm tired of this sh*t. Everything was better in the old days :[
– Nilzor
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Turn a simple socket into an SSL socket
...()
{
SSL_load_error_strings();
SSL_library_init();
OpenSSL_add_all_algorithms();
}
void DestroySSL()
{
ERR_free_strings();
EVP_cleanup();
}
void ShutdownSSL()
{
SSL_shutdown(cSSL);
SSL_free(cSSL);
}
Now for the bulk of the functionality. You may want to add a while lo...
Removing multiple keys from a dictionary safely
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Why not like this:
entries = ('a', 'b', 'c')
the_dict = {'b': 'foo'}
def entries_to_remove(entries, the_dict):
for key in entries:
if key in the_dict:
del the_dict[key]
A more compact version was provided by mattbornski using dict.pop()
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How to compare two dates in php
How to compare two dates in php if dates are in format '03_01_12' and '31_12_11' .
15 Answers
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Android Studio inline compiler showing red errors, but compilation with gradle works fine
... Deleting everything in .idea directory is a bad idea, as it might reset all project settings. Just removing .idea/libraries and .idea/caches finally solved the problem for me after trying all other solutions.
– fdermishin
May 17 '18 at 15:56
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How can I create download link in HTML?
... new browser window appear before the download starts. That window will usually be closed when the browser discovers that the resource is a file download.
Note that file types known to the browser (e.g. JPG or GIF images) will usually be opened within the browser.
You can try sending the right hea...