我正在尝试安装Tensorflow对象检测API,遵循的步骤,这是Tensorflow 2的正式安装文档。
git clone https://github.com/tensorflow/models.git
> everything is ok
cd models/research/
> everything is ok
protoc object_detection/protos/*.proto --python_out=.
> everything is ok
cp object_detection/packages/tf2/setup.py .
> everyt
我正在使用with解析和几个子解析器。我希望我的程序在args中的任何地方,包括子解析器中,都可以选择详细的内容。
from argparse import ArgumentParser
p = ArgumentParser()
p.add_argument('--verbose', '-v', action='count')
sub = p.add_subparsers()
a = sub.add_parser('a')
print(p.parse_args())
默认情况下,如果用于子解析器,主解析器的选项将引发错误:
$
我有一个脚本,它在Python2.7.3和2.7.5+中没有重大缺陷,但不能使用2.7.6。我怀疑这可能与Beautifulsoup如何处理unicode有关,但我不确定。
它基本上是这样做的:
# harvest HTML, store it in the variable html
html = harvest()
# the HTML is a string of ascii characters (no extended anything)
soup = BeautifulSoup(html)
trs = soup.find_all('tr',event_attr_id
所以我有一个with语句的简单例子。它在Python3.8和3.9中工作:
class Foo:
def __enter__(self, *args):
print("enter")
def __exit__(self, *args):
print("exit")
with Foo() as f, Foo() as b:
print("Foo")
产出(如预期):
enter
enter
Foo
exit
exit
但是,如果添加像这样的括号,它只适用于Python3.9:
class
安装BeautifulSoup后,每当我在命令行中运行Python时,就会发出以下警告:
D:\Application\python\lib\site-packages\beautifulsoup4-4.4.1-py3.4.egg\bs4\__init__.py:166:
UserWarning: No parser was explicitly specified, so I'm using the best
available HTML parser for this system ("html.parser"). This usually isn't a