大约有 47,000 项符合查询结果（耗时：0.0585秒） [XML]
What is the best way to implement nested dictionaries?
...ython?
This is a bad idea, don't do it. Instead, use a regular dictionary and use dict.setdefault where apropos, so when keys are missing under normal usage you get the expected KeyError. If you insist on getting this behavior, here's how to shoot yourself in the foot:
Implement __missing__ on a di...
Preventing Laravel adding multiple records to a pivot table
I have a many to many relationship set up and working, to add an item to the cart I use:
5 Answers
...
Pass a JavaScript function as parameter
..."Hello World!") });
If you prefer, you could also use the apply function and have a third parameter that is an array of the arguments, like such:
function eat(food1, food2)
{
alert("I like to eat " + food1 + " and " + food2 );
}
function myFunc(callback, args)
{
//do stuff
//...
/...
Is there a printf converter to print in binary format?
...a function as the argument to BYTE_TO_BINARY) but avoids the memory issues and multiple invocations of strcat in some of the other proposals here.
share
|
improve this answer
|
...
What is the difference between ~> and >= when specifying rubygem in Gemfile?
...constraint. RubyGems will increment the last digit in the version provided and use that until it reaches a maximum version. So ~>0.8.5 is semantically equivalent to:
gem "cucumber", ">=0.8.5", "<0.9.0"
The easy way to think about it is that you're okay with the last digit incrementing to ...
Git diff says subproject is dirty
I have just run a git diff, and I am getting the following output for all of my approx 10 submodules
9 Answers
...
Remove rows with all or some NAs (missing values) in data.frame
... 1 2 3 2
but using complete.cases is quite a lot more clear, and faster.
share
|
improve this answer
|
follow
|
...
Can't connect to local MySQL server through socket homebrew
I recently tried installing MySQL with homebrew ( brew install mysql ) and when I try to run it I get the following error:
...
How do I rename a column in a SQLite database table?
...has been asked on stackoverflow previously, but it was for SQL in general, and the case of SQLite was not mentioned.
15 Ans...
Fast way to discover the row count of a table in PostgreSQL
...IN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relname = 'mytable'
AND n.nspname = 'myschema'
Or better still
SELECT reltuples::bigint AS estimate
FROM pg_class
WHERE oid = 'myschema.mytable'::regclass;
Faster, simpler, safer, more elegant. See the manual on Object Identifier Type...