大约有 47,000 项符合查询结果（耗时：0.1642秒） [XML]
pandas: filter rows of DataFrame with operator chaining
...
Since version 0.18.1 the .loc method accepts a callable for selection. Together with lambda functions you can create very flexible chainable filters:
import numpy as np
import pandas as pd
df = pd.DataFrame(np.random.randint(0,100,size=(100, 4)), columns=list('ABCD'))
df.loc[lambda ...
Start a git commit message with a hashmark (#)
...y that behavior is wanted.
git 2.0.x/2.1 (Q3 2014) will add an automatic selection for core.commentChar:
See commit 84c9dc2
When core.commentChar is "auto", the comment char starts with '#' as in default but if it's already in the prepared message, find another char in a small subset. This should...
Why is Node.js single threaded? [closed]
...d memory is the limiting factor. In the event loop model, the loop thread selects the next event (I/O finished) to handle. So the thread is always busy (if you program it correctly of course).
The event loop model as all new things seems shiny and the solution for all issues but which model to us...
How to get a table cell value using jQuery?
...p the class attribute with it.
By the way, I think you could do it in one selector:
$('#mytable .customerIDCell').each(function() {
alert($(this).html());
});
If that makes things easier.
share
|
...
Convert data.frame columns from factors to characters
... can create a logical vector of which columns are factors, and use that to selectively apply factor
f <- sapply(bobf, class) == "factor"
bobc[,f] <- lapply(bobc[,f], factor)
share
|
improve ...
How do I truncate a .NET string?
...inqpad extension methods)
var val = string.Concat(Enumerable.Range(0, 50).Select(i => i % 10));
foreach(var limit in new[] { 10, 25, 44, 64 })
new Perf<string> {
{ "newstring" + limit, n => new string(val.Take(limit).ToArray()) },
{ "concat" + limit, n => string....
How to write a simple database engine [closed]
...h pattern of delimiter is never used in your data itself. i.e. if you have selected <*> for example to separate columns, you should validate the data you are placing in this table not to contain this pattern. you could also use a row header and a column header by specifying size of row and som...
How to retrieve a file from a server via SFTP?
...mote-username", "remote-host" );
{
// "interactive" version
// can selectively update specified known_hosts file
// need to implement UserInfo interface
// MyUserInfo is a swing implementation provided in
// examples/Sftp.java in the JSch dist
UserInfo ui = new MyUserInfo();
ses...
pull out p-values and r-squared from a linear regression
... need. The beta, se, t and p vectors are stored in it. Get the p-values by selecting the 4th column of the coefficients matrix (stored in the summary object):
summary(fit)$coefficients[,4]
summary(fit)$r.squared
Try str(summary(fit)) to see all the info that this object contains.
Edit: I had ...
How to version control a record in a database
...tDate of the second record.
When you want to view the current record, you select the one where endDate is null.
This is sometimes called a type 2 Slowly Changing Dimension.
See also TupleVersioning
share
|
...