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str performance in python
While profiling a piece of python code ( python 2.6 up to 3.2 ), I discovered that the
str method to convert an object (in my case an integer) to a string is almost an order of magnitude slower than using string formatting.
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Bash conditionals: how to “and” expressions? (if [ ! -z $VAR && -e $VAR ])
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edited Dec 22 '14 at 22:36
answered Jan 19 '12 at 2:16
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Stop pip from failing on single package when installing with requirements.txt
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238
Running each line with pip install may be a workaround.
cat requirements.txt | xargs -n 1 pip...
UPDATE multiple tables in MySQL using LEFT JOIN
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UPDATE t1
LEFT JOIN
t2
ON t2.id = t1.id
SET t1.col1 = newvalue
WHERE t2.id IS NULL
Note that for a SELECT it would be more efficient to use NOT IN / NOT EXISTS syntax:
SELECT t1.*
FROM t1
WHERE t1.id NOT IN
(
S...
How to get last inserted row ID from WordPress database?
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edited Apr 7 '19 at 14:28
Maxime
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answered Oct...
How do I print the elements of a C++ vector in GDB?
...uce an output similar to:
$1 = std::vector of length 3, capacity 4 = {10, 20, 30}
To achieve above, you need to have gdb 7 (I tested it on gdb 7.01) and some python pretty-printer. Installation process of these is described on gdb wiki.
What is more, after installing above, this works well with ...
enum - getting value of enum on string conversion
...:
def __str__(self):
return str(self.value)
x = 1
y = 2
Demo:
>>> from enum import Enum
>>> class D(Enum):
... def __str__(self):
... return str(self.value)
... x = 1
... y = 2
...
>>> D.x
<D.x: 1>
>>> print(D.x)
...
How do I query using fields inside the new PostgreSQL JSON datatype?
...g for some docs and/or examples for the new JSON functions in PostgreSQL 9.2.
3 Answers
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Why is using the rails default_scope often recommend against?
...explict when wanting to show unpublished (private) posts. So far so good.
2.1.1 :001 > Post.all
Post Load (0.2ms) SELECT "posts".* FROM "posts" WHERE "posts"."published" = 't'
Well this is pretty much what we expect. Now lets try:
2.1.1 :004 > Post.new
=> #<Post id: nil, title:...
Creating JS object with Object.create(null)?
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200
They are not equivalent. {}.constructor.prototype == Object.prototype while Object.create(null...