大约有 40,000 项符合查询结果（耗时：0.0466秒） [XML]
Getting attribute using XPath
...e right way to get it. This is just an assumption where as you have a book table TITLE and PRICE column with populated data. Here's the query
SELECT xpath('/bookstore/book/title/@lang', xmlforest(book.title AS title, book.price AS price), ARRAY[ARRAY[]::TEXT[]]) FROM book LIMIT 1;
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How do I log a Python error with debug information?
...g.exception("message")
Output:
ERROR:root:message
Traceback (most recent call last):
File "<stdin>", line 2, in <module>
ZeroDivisionError: integer division or modulo by zero
@Paulo Cheque notes, "be aware that in Python 3 you must call the logging.exception method just inside the ex...
What is a None value?
...n't write the sticker "F", there was already an F sticker on the None, and all you did was move it, from None to "fork". So when you type F = None, you're "reset[ting] it to its original, empty state", if we decided to treat None as meaning empty state.
I can see what he's getting at, but that's a...
R - Markdown avoiding package loading messages
...clude=FALSE,}
knitr::opts_chunk$set(echo = TRUE, warning=FALSE)
#formating tables
library(xtable)
#data wrangling
library(dplyr)
#text processing
library(stringi)
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__lt__ instead of __cmp__
...ttributes of the new class it's decorating (the result might be microscopically faster at runtime, at equally minute cost in terms of memory).
Of course, if your class has some particularly fast way to implement (e.g.) __eq__ and __ne__, it should define them directly so the mixin's versions are no...
How to ignore user's time zone and force Date() use specific time zone
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A Date object's underlying value is actually in UTC. To prove this, notice that if you type new Date(0) you'll see something like: Wed Dec 31 1969 16:00:00 GMT-0800 (PST). 0 is treated as 0 in GMT, but .toString() method shows the local time.
Big note, UTC stands ...
What is the current state of the art in HTML canvas JavaScript libraries and frameworks? [closed]
...s Fabric compare to other Javascript canvas libraries? Here's a comparison table.
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StringBuilder vs String concatenation in toString() in Java
...o builder?
At the point where you're concatenating in a loop - that's usually when the compiler can't substitute StringBuilder by itself.
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foll...
Best practices for circular shift (rotate) operations in C++
...,7 which is slower and takes more bytes than rol edi,7 on some CPUs (especially AMD, but also some Intel), when BMI2 isn't available for rorx eax,edi,25 to save a MOV.
MSVC: x86-64 CL19: Only recognized for constant-count rotates. (The wikipedia idiom is recognized, but the branch and AND aren't op...
How do you programmatically set an attribute?
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Damn shame it doesn't work in all cases, as that would be really useful, for example, for adding the dirty attribute to user input...
– brice
Feb 28 '12 at 18:32
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