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The tilde operator in Python
...a unary operator (taking a single argument) that is borrowed from C, where all data types are just different ways of interpreting bytes. It is the "invert" or "complement" operation, in which all the bits of the input data are reversed.
In Python, for integers, the bits of the twos-complement repr...
Using python's eval() vs. ast.literal_eval()?
...
datamap = eval(raw_input('Provide some data here: ')) means that you actually evaluate the code before you deem it to be unsafe or not. It evaluates the code as soon as the function is called. See also the dangers of eval.
ast.literal_eval raises an exception if the input isn't a valid Python dat...
How to track untracked content?
...plugins/open_flash_chart_2 starts out as an independent Git repository. Usually such sub-repositories are ignored, but if you tell git add to explicitly add it, then it will create an gitlink entry that points to the sub-repository’s HEAD commit instead of adding the contents of the directory. It ...
What is the difference between a static and a non-static initialization code block
...own, just like simple variable initializers) when the class is loaded (actually, when it's resolved, but that's a technicality).
Instance initializers are executed in the order defined when the class is instantiated, immediately before the constructor code is executed, immediately after the invocat...
tinyxml XML解析库下载(tinyxml2.h 和 tinyxml2.cpp) - 源码下载 - 清泛...
...>
# include <cstdarg>
#endif
/*
TODO: intern strings instead of allocation.
*/
/*
gcc:
g++ -Wall -DDEBUG tinyxml2.cpp xmltest.cpp -o gccxmltest.exe
Formatting, Artistic Style:
AStyle.exe --style=1tbs --indent-switches --break-closing-brackets --indent-preproce...
Hashing a dictionary?
...e hash():
hash(frozenset(my_dict.items()))
This is much less computationally intensive than generating the JSON string or representation of the dictionary.
UPDATE: Please see the comments below, why this approach might not produce a stable result.
...
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...
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 = ...
How to make a chain of function decorators?
...her object
scream = shout
# Notice we don't use parentheses: we are not calling the function,
# we are putting the function "shout" into the variable "scream".
# It means you can then call "shout" from "scream":
print(scream())
# outputs : 'Yes!'
# More than that, it means you can remove the old...
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...