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Flask-SQLalchemy update a row's information
...tutorial shown in the Flask-SQLAlchemy documentation. Once you have the entity that you want to change, change the entity itself. Then, db.session.commit().
For example:
admin = User.query.filter_by(username='admin').first()
admin.email = 'my_new_email@example.com'
db.session.commit()
user = User...
Assigning a variable NaN in python without numpy
...stant you can use to assign a variable the value NaN. Can python do this without using numpy?
6 Answers
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Rails: around_* callbacks
...cks are invoked before the action, then when you want to invoke the action itself, you yield to it, then continue execution. That's why it's called around
The order goes like this: before, around, after.
So, a typical around_save would look like this:
def around_save
#do something...
yield ...
Dashed line border around UIView
...
You can set the border with this pattern using Layer and Bezier path like below examples.
Objective-C
CAShapeLayer *yourViewBorder = [CAShapeLayer layer];
yourViewBorder.strokeColor = [UIColor blackColor].CGColor;
yourViewBorder.fillColor = nil;
y...
C++对象布局及多态探索之菱形结构虚继承 - C/C++ - 清泛网 - 专注C/C++及内核技术
...0则从C100和C101多重继承而来。
struct C041
{
C041() : c_(0x01) {}
virtual void foo() { c_ = 0x02; }
char c_;
};
struct C100 : public virtual C041
{
C100() : c_(0x02) {}
char c_;
};
struct C101 : public virtual C041
{
C101() : c_(0x03) {}
...
How to copy a row and insert in same table with a autoincrement field in MySQL?
In MySQL I am trying to copy a row with an autoincrement column ID=1 and insert the data into same table as a new row with column ID=2 .
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What is in your Mathematica tool bag? [closed]
We all know that Mathematica is great, but it also often lacks critical functionality. What kind of external packages / tools / resources do you use with Mathematica?
...
What are 'closures' in .NET?
...
I have an article on this very topic. (It has lots of examples.)
In essence, a closure is a block of code which can be executed at a later time, but which maintains the environment in which it was first created - i.e. it can still use the local variables etc of t...
OceanBase使用libeasy原理源码分析：服务器端 - 数据库(内核) - 清泛网 - ...
...、OceanBase启动时的使用模式
二、 基础数据结构
2.1 easy_list_t
2.2 easy_pool_t
2.3 easy_buf_t
2.4 easy_connection_t
三、 连接建立
四、 同步处理(OceanBase少量使用这种模式)
五、 异步处理(OceanBase大量采用这种模式)
六、 资源管理
...
What is the fastest way to send 100,000 HTTP requests in Python?
...looked at the python concurrence library, but cannot figure out how to write this program correctly. Has anyone come across a similar problem? I guess generally I need to know how to perform thousands of tasks in Python as fast as possible - I suppose that means 'concurrently'.
...