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Django-Admin: CharField as TextArea
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Starting from Django 1.7 you need to add also fields = '__all__' under class Meta:.
– skoll
May 4 '16 at 11:43
2
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Why is reading lines from stdin much slower in C++ than Python?
...tl;dr: Because of different default settings in C++ requiring more system calls.
By default, cin is synchronized with stdio, which causes it to avoid any input buffering. If you add this to the top of your main, you should see much better performance:
std::ios_base::sync_with_stdio(false);
Normall...
Specifying an Index (Non-Unique Key) Using JPA
...Table;
@Entity
@Table(name = "region",
indexes = {@Index(name = "my_index_name", columnList="iso_code", unique = true),
@Index(name = "my_index_name2", columnList="name", unique = false)})
public class Region{
@Column(name = "iso_code", nullable = false)
priva...
To ARC or not to ARC? What are the pros and cons? [closed]
...t has no GC runtime overhead. The compiler inserts retains and releases in all the places you should have anyway. But it's smarter than you and can optimize out the ones that aren't actually needed (just like it can unroll loops, eliminate temporary variables, inline functions, etc.)
OK, now I will...
C++ catching all exceptions
...
try{
// ...
} catch (...) {
// ...
}
will catch all C++ exceptions, but it should be considered bad design. You can use c++11's new current_exception mechanism, but if you don't have the ability to use c++11 (legacy code systems requiring a rewrite), then you have no name...
Django admin: how to sort by one of the custom list_display fields that has no database field
How could I sort Customers, depending on number_of_orders they have?
3 Answers
3
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Why can lambdas be better optimized by the compiler than plain functions?
...assing them to a function template will instantiate a new function specifically for that object. The compiler can thus trivially inline the lambda call.
For functions, on the other hand, the old caveat applies: a function pointer gets passed to the function template, and compilers traditionally hav...
How to run a python script from IDLE interactive shell?
...s.call(['python', 'helloworld.py']) # Just run the program
subprocess.check_output(['python', 'helloworld.py']) # Also gets you the stdout
With arguments:
subprocess.call(['python', 'helloworld.py', 'arg'])
Read the docs for details :-)
Tested with this basic helloworld.py:
import sys
if le...
What is the colon operator in Ruby?
..." # false
:foo.equal? :foo # true
This makes comparing two symbols really fast (since only a pointer comparison is involved, as opposed to comparing all the characters like you would in a string), plus you won't have a zillion copies of the same symbol floating about.
Also, unlike strings, sy...
Difference between passing array and array pointer into function in C
... eax, 0Fh
add eax, 0Fh
shr eax, 4
shl eax, 4
mov [ebp+var_C], eax
mov eax, [ebp+var_C]
call sub_401730
call sub_4013D0
mov [ebp+var_8], 2
mov [ebp+var_4], 4
lea eax, [ebp+var_8]
mov [esp+18h+var_18], eax
call sub_401290
call _getch
leave
retn
So th...