大约有 47,000 项符合查询结果（耗时：0.0487秒） [XML]
Pandas - How to flatten a hierarchical index in columns
...ant to combine/join your MultiIndex into one Index (assuming you have just string entries in your columns) you could:
df.columns = [' '.join(col).strip() for col in df.columns.values]
Note: we must strip the whitespace for when there is no second index.
In [11]: [' '.join(col).strip() for col in...
A Regex that will never be matched by anything
...plementation / flags*:
$a
Will match a character a after the end of the string. Good luck.
WARNING:
This expression is expensive -- it will scan the entire line, find the end-of-line anchor, and only then not find the a and return a negative match. (See comment below for more detail.)
* Origi...
When to use lambda, when to use Proc.new?
...om :0
irb(main):006:0> p.call "hello"
TypeError: can't convert nil into String
from (irb):2:in `+'
from (irb):2
from (irb):6:in `call'
from (irb):6
from :0
The page also recommends using lambda unless you specifically want the error tolerant behavior. I agree with this senti...
how to get GET and POST variables with JQuery?
...actually empty, you will get a javascript syntax error. If you know it's a string, you should wrap it in quotes. If it's an integer, you may want to test to see if it actually exists before writing the line to javascript.
sh...
Initializing a static std::map in C++
...
I'm using your first sample as <int,string> to bind error-numbers (from an enum) with messages - it is working like a charm - thank you.
– slashmais
Sep 22 '10 at 10:57
...
How do you read CSS rule values with JavaScript?
I would like to return a string with all of the contents of a CSS rule, like the format you'd see in an inline style. I'd like to be able to do this without knowing what is contained in a particular rule, so I can't just pull them out by style name (like .style.width etc.)
...
Confused about __str__ on list in Python [duplicate]
...round, I understand that __str__ is something like a Python version of toString (while I do realize that Python is the older language).
...
Easiest way to detect Internet connection on iOS?
...all native C code snippet that can check internet connectivity without any extra class.
Add the following headers:
#include<unistd.h>
#include<netdb.h>
Code:
-(BOOL)isNetworkAvailable
{
char *hostname;
struct hostent *hostinfo;
hostname = "google.com";
hostinfo = get...
YAML current date in rmarkdown
... a list includes: after_body: [ ... ] as valid YAML would only be filename strings... So no possibility of includes: "`r list.files(...)`" ?
– Louis Maddox
Mar 2 '15 at 18:33
...
How do i find out what all symbols are exported from a shared object?
...ning: Cannot initialize program headers
Warning: Cannot initialize dynamic strings
Warning: Cannot initialize dynamic section
[Symbols]
vaddr=0x08000149 paddr=0x00000149 ord=006 fwd=NONE sz=1 bind=LOCAL type=OBJECT name=std::piecewise_construct
vaddr=0x08000149 paddr=0x00000149 ord=007 fwd=NONE sz=1...