大约有 45,000 项符合查询结果（耗时：0.0355秒） [XML]
Which is better in python, del or delattr?
.... del foo.bar compiles to two bytecode instructions:
2 0 LOAD_FAST 0 (foo)
3 DELETE_ATTR 0 (bar)
whereas delattr(foo, "bar") takes five:
2 0 LOAD_GLOBAL 0 (delattr)
3 LOAD_FAST 0 (foo)
...
Why can't (or doesn't) the compiler optimize a predictable addition loop into a multiplication?
...
It does now -- at least, clang does:
long long add_100k_signed(int *data, int arraySize)
{
long long sum = 0;
for (int c = 0; c < arraySize; ++c)
if (data[c] >= 128)
for (int i = 0; i < 100000; ++i)
sum += data[c];
re...
Why does 'continue' behave like 'break' in a Foreach-Object?
..., it simulates the continue in a loop.
1..100 | ForEach-Object {
if ($_ % 7 -ne 0 ) { return }
Write-Host "$($_) is a multiple of 7"
}
There is a gotcha to be kept in mind when refactoring. Sometimes one wants to convert a foreach statement block into a pipeline with a ForEach-Object cmdl...
What is setup.py?
...ts and also from [I]Python prompts.
It does the similar job of pip, easy_install etc.,
Using setup.py
Let's start with some definitions:
Package - A folder/directory that contains __init__.py file.
Module - A valid python file with .py extension.
Distribution - How one package relates to ...
Encoding an image file with base64
...long the lines of:
import base64
with open("yourfile.ext", "rb") as image_file:
encoded_string = base64.b64encode(image_file.read())
You have to open the file first of course, and read its contents - you cannot simply pass the path to the encode function.
Edit:
Ok, here is an update after y...
unbound method f() must be called with fibo_ instance as first argument (got classobj instance inste
...thod() to access parent methods.
class ParentClass(object):
def method_to_call(self, arg_1):
print arg_1
class ChildClass(ParentClass):
def do_thing(self):
super(ChildClass, self).method_to_call('my arg')
...
MLKitEntityExtractor 拓展：文本实体抽取（地址/日期/电话/金额/快递单号...
...会自动先下载再抽取。
实体类型给可读名称（PHONE、DATE_TIME）而不是数字编号。
支持 15 种语言，默认中文。
常用场景：从短信/聊天记录里自动识别快递单号和验证码、把一段话里的时间地点变成日程、
从名片文字里提取...
Are there any reasons to use private properties in C#?
... them if I need to cache a value and want to lazy load it.
private string _password;
private string Password
{
get
{
if (_password == null)
{
_password = CallExpensiveOperation();
}
return _password;
}
}
...
Javascript regex returning true.. then false.. then true.. etc [duplicate]
...
/^[^-_]([a-z0-9-_]{4,20})[^-_]$/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 ...
How can I use UUIDs in SQLAlchemy?
... is an example:
from sqlalchemy.dialects.postgresql import UUID
from flask_sqlalchemy import SQLAlchemy
import uuid
db = SQLAlchemy()
class Foo(db.Model):
# id = db.Column(db.Integer, primary_key=True)
id = db.Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4, unique=True, n...