大约有 40,000 项符合查询结果（耗时：0.0250秒） [XML]
How to check if variable is string with python 2 and 3 compatibility
...
Nice, but why? It would be nice if Python3 would be backward-compatible here. Above solutions works. Would be even better, if there would be no need for it.
– guettli
Mar 4 '19 at 19:37
...
Are tuples more efficient than lists in Python?
...gives tuples a small speed advantage for indexed lookups and unpacking:
$ python3.6 -m timeit -s 'a = (10, 20, 30)' 'a[1]'
10000000 loops, best of 3: 0.0304 usec per loop
$ python3.6 -m timeit -s 'a = [10, 20, 30]' 'a[1]'
10000000 loops, best of 3: 0.0309 usec per loop
$ python3.6 -m timeit -s 'a ...
How to install psycopg2 with “pip” on Python?
... package from source:
Debian/Ubuntu
Python 3
sudo apt install libpq-dev python3-dev
You might need to install python3.8-dev or similar for e.g. Python 3.8.
Python 21
sudo apt install libpq-dev python-dev
If that's not enough, try
sudo apt install build-essential
or
sudo apt install post...
How to avoid “RuntimeError: dictionary changed size during iteration” error?
...
your python3 solution is not work when you want to delete an object in inner dict. for example you have a dic A and dict B in dict A. if you want to delete object in dict B it occurs error
– Ali-T
...
How to import other Python files?
...
Is it still accurate in 2019? Is it python3 or 2?
– Sandburg
Jan 24 '19 at 11:34
|
show 2 more commen...
How do I update pip itself from inside my virtual environment?
...https://bootstrap.pypa.io/get-pip.py -O ./get-pip.py
python ./get-pip.py
python3 ./get-pip.py
This will install the current version which at the time of writing this solution is 9.0.1 which is way beyond what Debian provides.
$ pip --version
pip 9.0.1 from /home/myhomedir/myvirtualenvdir/lib/...
How to run code when a class is subclassed? [duplicate]
...s:
__metaclass__ = Watcher
where Watcher is a subclass of type.
In Python3 the syntax has been changed to
class SuperClass(metaclass=Watcher)
Both are equivalent to
Superclass = Watcher(name, bases, clsdict)
where in this case, name equals the string 'Superclass', and bases is the tupl...
Setting Django up to use MySQL
...
If you are using python3.x then Run below command
pip install mysqlclient
Then change setting.py like
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'DB',
'USER': 'username',
'PASSWORD': 'passwd'...
C++并发编程（中文版） - 文档下载 - 清泛网 - 专注C/C++及内核技术
C++并发编程（中文版）C++并发编程（中文版）作为对《C++ Concurrency in Action》的中文翻译。本书是基于C++11新标准的并发和多线程编程深度指南。从std::thr 作为对《C++ Concurrency in Action》的中文翻译。
本书是基于C++11新标准的并...
How to beautify JSON in Python?
... here, it also includes a line using json.dumps() Using it with aiohttp on python3.7, didn't need to use the sys module and unicode(String, encoding). Basically it becomes == highlight(formatted_json, lexers.JsonLexer(), formatters.TerminalFormatter())
– DanglingPointer
...