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Unique fields that allow nulls in Django
...pty string by providing your own customized model form for Foo with a clean_bar method that turns the empty string into None:
class FooForm(forms.ModelForm):
class Meta:
model = Foo
def clean_bar(self):
return self.cleaned_data['bar'] or None
class FooAdmin(admin.ModelAdmin...
Substitute multiple whitespace with single whitespace in Python [duplicate]
...ce characters that are combined.
To match unicode whitespace:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"\s+")
my_str = _RE_COMBINE_WHITESPACE.sub(" ", my_str).strip()
To match ASCII whitespace only:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"(?a:\s+)")
_RE_STRIP_WHITESPACE = re.co...
Convert a float64 to an int in Go
...problem in Go that can be unexpected (at least if you come from Java): "In all non-constant conversions involving floating-point or complex values, if the result type cannot represent the value the conversion succeeds but the result value is implementation-dependent." (golang.org/ref/spec#Conversion...
django : using select_related and get_object_or_404 together
Is there any way of using get_object_or_404 and select_related together or any other way to achieve the result of using these two together(except from putting it in try/except)??
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When to use reinterpret_cast?
...time hence the word static . This is the cast the C++ compiler uses internally for implicit casts also.
11 Answers
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In Perl, how can I read an entire file into a string?
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before reading from the file handle. See How can I read in an entire file all at once?, or
$ perldoc -q "entire file"
See Variables related to filehandles in perldoc perlvar and perldoc -f local.
Incidentally, if you can put your script on the server, you can have all the modules you want. See ...
How does free know how much to free?
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FYI, for example BSD has malloc_size() to reliably access the block size from an malloc()ed pointer. But there's no reliable, portable way.
– laalto
Oct 5 '09 at 7:53
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Why can't I forward-declare a class in a namespace using double colons?
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All other answers were confusing to me but this "you can't declare a class within a namespace from outside that namespace. You have to be in the namespace." was very helpful hint to remember.
– dashesy
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Using curl to upload POST data with files
... I think its really useful.
public function postFile()
{
$file_url = "test.txt"; //here is the file route, in this case is on same directory but you can set URL too like "http://examplewebsite.com/test.txt"
$eol = "\r\n"; //default line-break for mime type
$BOUNDARY = m...
MySQL: determine which database is selected?
After calling mysql_select_db to grab a database, is there any way to later output the name of the database that is currently selected? This seems very basic but I couldn't find anything on php.net or stackoverflow (all results are for "no database selected").
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