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Python argparse mutual exclusive group
...
add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive.
What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd hav...
腾讯Tencent开源框架介绍（持续更新） - 开源 & Github - 清泛网 - 专注C/C++及内核技术
...h>
#include <stdio.h>
#include <stdlib.h>
#include <queue>
#include "co_routine.h"
using namespace std;
/**
* 本实例是对条件变量的展示，其作用类似于pthread_cond_wait
*/
struct stTask_t
{
int id;
};
struct stEnv_t
{
stCoCond_t* cond;
queue<stTask_t*> task_queue...
How to compare type of an object in Python?
...
isinstance works:
if isinstance(obj, MyClass): do_foo(obj)
but, keep in mind: if it looks like a duck, and if it sounds like a duck, it is a duck.
EDIT: For the None type, you can simply do:
if obj is None: obj = MyClass()
...
sqlalchemy: how to join several tables by one query?
...integer primary keys for everything, but whatever):
class User(Base):
__tablename__ = 'users'
email = Column(String, primary_key=True)
name = Column(String)
class Document(Base):
__tablename__ = "documents"
name = Column(String, primary_key=True)
author_email = Column(Strin...
Javascript regex returning true.. then false.. then true.. etc [duplicate]
...
/^[^-_]([a-z0-9-_]{4,20})[^-_]$/gi;
You're using a g (global) RegExp. In JavaScript, global regexen have state: you call them (with exec, test etc.) the first time, you get the first match in a given string. Call them again and ...
Does C++ support 'finally' blocks? (And what's this 'RAII' I keep hearing about?)
...ing a mutex:
// A class with implements RAII
class lock
{
mutex &m_;
public:
lock(mutex &m)
: m_(m)
{
m.acquire();
}
~lock()
{
m_.release();
}
};
// A class which uses 'mutex' and 'lock' objects
class foo
{
mutex mutex_; // mutex for l...
Project structure for Google App Engine
... had trouble with packages. Just make sure each of your sub folders has an __init__.py file. It's ok if its empty.
Boilerplate files
These hardly vary between projects
app.yaml: direct all non-static requests to main.py
main.py: initialize app and send it all requests
Project lay-out
static...
Get name of object or class
... use standard IIFE (for example with TypeScript)
var Zamboch;
(function (_Zamboch) {
(function (Web) {
(function (Common) {
var App = (function () {
function App() {
}
App.prototype.hello = function () {
co...
Which characters are valid in CSS class names/selectors?
...tly at the CSS grammar.
Basically1, a name must begin with an underscore (_), a hyphen (-), or a letter(a–z), followed by any number of hyphens, underscores, letters, or numbers. There is a catch: if the first character is a hyphen, the second character must2 be a letter or underscore, and the n...
How to print a dictionary line by line in Python?
...
I do print(json.dumps(cars, indent=4, ensure_ascii=False)) because otherwise non-ASCII characters are unreadable.
– Boris
Apr 22 at 16:36
add a ...