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How do I add a placeholder on a CharField in Django?

... Look at the widgets documentation. Basically it would look like: q = forms.CharField(label='search', widget=forms.TextInput(attrs={'placeholder': 'Search'})) More writing, yes, but the separation allows for better abstraction of more complic...
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Do try/catch blocks hurt performance when exceptions are not thrown?

... { Console.WriteLine(ex.ToString()); } finally { d = Math.Sin(d); } } w.Stop(); Console.Write(" try/catch/finally: "); Console.WriteLine(w.ElapsedMilliseconds); w.Reset(); d = 0; w.Start(); for (int i = ...
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How do I determine the size of an object in Python?

...turn the size of an object in bytes. The object can be any type of object. All built-in objects will return correct results, but this does not have to hold true for third-party extensions as it is implementation specific. Only the memory consumption directly attributed to the object is accounted for...
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Ora-00257 错误处理一列 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术

... 没有问题 查看权限 ll .bash_profile -rw--rw--- 1 oracle oinstall 529 10鏈?24 20:18 /home/oracle/.bash_profile 有问题。修改权限 chmod 775 /home/oracle/.bash_profile 进入ORLACE sqlplus /as sysdba SQL> select * from v$log; GROUP# THREAD# SEQUE...
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How do I get the result of a command in a variable in windows?

... If you have to capture all the command output you can use a batch like this: @ECHO OFF IF NOT "%1"=="" GOTO ADDV SET VAR= FOR /F %%I IN ('DIR *.TXT /B /O:D') DO CALL %0 %%I SET VAR GOTO END :ADDV SET VAR=%VAR%!%1 :END All output lines are stor...
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Why is __init__() always called after __new__()?

... new instance. __new__ is the first step of instance creation. It's called first, and is responsible for returning a new instance of your class. In contrast, __init__ doesn't return anything; it's only responsible for initializing the instance after it's been created. In ge...
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Why can't I overload constructors in PHP?

I have abandoned all hope of ever being able to overload my constructors in PHP, so what I'd really like to know is why . ...
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How do I run all Python unit tests in a directory?

...it test module is of the form test_*.py . I am attempting to make a file called all_test.py that will, you guessed it, run all files in the aforementioned test form and return the result. I have tried two methods so far; both have failed. I will show the two methods, and I hope someone out there ...
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How to do relative imports in Python?

... the module were a top level module, regardless of where the module is actually located on the file system. In Python 2.6, they're adding the ability to reference modules relative to the main module. PEP 366 describes the change. Update: According to Nick Coghlan, the recommended alternative is ...
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node.js require all files in a folder?

How do I require all files in a folder in node.js? 14 Answers 14 ...