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Right way to reverse pandas.DataFrame?
...ata.Odd[idx])
You are getting an error because reversed first calls data.__len__() which returns 6. Then it tries to call data[j - 1] for j in range(6, 0, -1), and the first call would be data[5]; but in pandas dataframe data[5] means column 5, and there is no column 5 so it will throw an exceptio...
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...
How to set top-left alignment for UILabel for iOS application?
...turn nil;
// set inital value via IVAR so the setter isn't called
_verticalAlignment = VerticalAlignmentTop;
return self;
}
-(VerticalAlignment) verticalAlignment
{
return _verticalAlignment;
}
-(void) setVerticalAlignment:(VerticalAlignment)value
{
_verticalAlignment = value...
Should I use encodeURI or encodeURIComponent for encoding URLs?
...
Here is a summary.
escape() will not encode @ * _ + - . /
Do not use it.
encodeURI() will not encode A-Z a-z 0-9 ; , / ? : @ & = + $ - _ . ! ~ * ' ( ) #
Use it when your input is a complete URL like 'https://searchexample.com/search?q=wiki'
encodeURIComponent() will ...
Tomcat: How to find out running tomcat version
....in/blog/check-jsp-tomcat-version
Save this code into a file called tomcat_version.jsp:
Tomcat Version : <%= application.getServerInfo() %><br>
Servlet Specification Version :
<%= application.getMajorVersion() %>.<%= application.getMinorVersion() %> <br> ...
dplyr: “Error in n(): function should not be called directly”
...ction" specification, like example below:
delay <- dplyr::summarise(by_tailnum,
count = n(),
dist = mean(distance, na.rm = TRUE),
delay = mean(arr_delay, na.rm = TRUE))
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improv...
How do I have an enum bound combobox with custom string formatting for enum values?
...ethod:
public struct Described<T> where T : struct {
private T _value;
public Described(T value) {
_value = value;
}
public override string ToString() {
string text = _value.ToString();
object[] attr =
typeof(T).GetField(text)
...
Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
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...
Managing constructors with many parameters in Java
...er the following example
public class StudentBuilder
{
private String _name;
private int _age = 14; // this has a default
private String _motto = ""; // most students don't have one
public StudentBuilder() { }
public Student buildStudent()
{
return new Student...
实战低成本服务器搭建千万级数据采集系统 - 更多技术 - 清泛网 - 专注C/C++...
...器。到了机器后再按照天或者半天分表，比如表名为 weibo_2013020101 、weibo_2013020112。weibo_2013020101表示2月1日上午一个表，weibo_2013020112表示2月1日下午一个表。光这样分了还是不够，1000w/2=500w，经不起压力扩展。我们还需要把表再...