大约有 36,200 项符合查询结果（耗时：0.0319秒） [XML]
Flask SQLAlchemy query, specify column names
...y the column that I want in my query using a model (it selects all columns by default)? I know how to do this with the sqlalchmey session: session.query(self.col1) , but how do I do it with with models? I can't do SomeModel.query() . Is there a way?
...
Simpler way to put PDB breakpoints in Python code?
...
You can run your program into pdb from the command line by running
python -m pdb your_script.py
It will break on the 1st line, then you'll be able to add a breakpoint wherever you want in your code using the break command, its syntax is:
b(reak) [[filename:]lineno | func...
pycharm running way slow
I'm a big fan of PyCharm by JetBrains but I do run into some issues that I thought maybe I'll ask here about.
9 Answers
...
Is there a way to get element by XPath using JavaScript in Selenium WebDriver?
...r.mozilla.org/en-US/docs/Web/API/Document.evaluate
function getElementByXpath(path) {
return document.evaluate(path, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
}
console.log( getElementByXpath("//html[1]/body[1]/div[1]") );
<div>foo</div>
...
Realistic usage of the C99 'restrict' keyword?
...liminates the potential for pointer aliasing, enabling better optimization by the compiler.
For instance, suppose I have a machine with specialized instructions that can multiply vectors of numbers in memory, and I have the following code:
void MultiplyArrays(int* dest, int* src1, int* src2, int n...
Efficient way to return a std::vector in c++
...1, this is the preferred way:
std::vector<X> f();
That is, return by value.
With C++11, std::vector has move-semantics, which means the local vector declared in your function will be moved on return and in some cases even the move can be elided by the compiler.
...
use Winmerge inside of Git to file diff
...ne 2012 (2-and-a-half years later):
Comparing directories instead of file-by-file will be available soon:
See [ANNOUNCE] Git 1.7.11.rc1:
"git difftool" learned the "--dir-diff" option to spawn external diff tools that can compare two directory hierarchies at a time after populating two temporar...
Does SQLAlchemy have an equivalent of Django's get_or_create?
...odel, defaults=None, **kwargs):
instance = session.query(model).filter_by(**kwargs).first()
if instance:
return instance, False
else:
params = dict((k, v) for k, v in kwargs.iteritems() if not isinstance(v, ClauseElement))
params.update(defaults or {})
ins...
What is the correct way of using C++11's range-based for?
...erations.
This is because we are capturing the elements from the container by value
(the auto x part in for (auto x : v)).
This is inefficient code, e.g., if these elements are instances of std::string,
heap memory allocations can be done, with expensive trips to the memory manager, etc.
This is u...
Can I embed a custom font in an iPhone application?
...fonts in their application bundle and register those fonts with the system by including the UIAppFonts key in their Info.plist file. The value of this key is an array of strings identifying the font files in the application’s bundle. When the system sees the key, it loads the specified fonts and m...