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Python None comparison: should I use “is” or ==?
My editor warns me when I compare my_var == None , but no warning when I use my_var is None .
3 Answers
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What's the difference between deque and list STL containers?
...that a horse works like a dog because they both implement attack() and make_noise().
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How to detect if a function is called as constructor?
... // except in in EcmaScript 5 strict mode.
&& !this.__previouslyConstructedByX) {
isConstructor = true;
this.__previouslyConstructedByX = true;
}
alert(isConstructor);
}
Obviously this is not ideal, since you now have an extra useless property on ever...
Programmatically stop execution of python script? [duplicate]
.... From Python's docs:
>>> import sys
>>> print sys.exit.__doc__
exit([status])
Exit the interpreter by raising SystemExit(status).
If the status is omitted or None, it defaults to zero (i.e., success).
If the status is numeric, it will be used as the system exit status.
If it is ...
Arduino101 陀螺仪 · App Inventor 2 中文网
...请求操作的结果。X和Y角度以度为单位报告。
参数:
* X_Angle (_number_) — 设备绕X轴旋转的角度，单位为度。
* Y_Angle (_number_) — 设备绕Y轴旋转的角度，单位为度。
您的改进建议 联系...
Sleep for milliseconds
... facilities:
#include <chrono>
#include <thread>
std::this_thread::sleep_for(std::chrono::milliseconds(x));
Clear and readable, no more need to guess at what units the sleep() function takes.
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How to get the width and height of an android.widget.ImageView?
...eight, finalWidth;
final ImageView iv = (ImageView)findViewById(R.id.scaled_image);
final TextView tv = (TextView)findViewById(R.id.size_label);
ViewTreeObserver vto = iv.getViewTreeObserver();
vto.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
...
Arduino101 湿度和温度 · App Inventor 2 中文网
...。湿度值是0-100%之间的相对湿度。
Parameters:
* humidity (_number_) — The relative humidity, in percent.
TemperatureReceived – 当从Arduino接收到温度样本时运行TemperatureReceived事件。
这通常是执行读取或请求
操作的结果。温度值以摄氏...
How can I convert JSON to CSV?
...this:
{
"pk": 22,
"model": "auth.permission",
"codename": "add_logentry",
"content_type": 8,
"name": "Can add log entry"
},
......]
Here is my code to generate CSV from that:
import csv
import json
x = """[
{
"pk": 22,
"model": "auth.permission",
...
#1071 - Specified key was too long; max key length is 1000 bytes
...per column as you define the index. For example:
...
KEY `index` (`parent_menu_id`,`menu_link`(50),`plugin`(50),`alias`(50))
...
But what's the best prefix length for a given column? Here's a method to find out:
SELECT
ROUND(SUM(LENGTH(`menu_link`)<10)*100/COUNT(`menu_link`),2) AS pct_leng...