大约有 47,000 项符合查询结果（耗时：0.0217秒） [XML]
How to check if all elements of a list matches a condition?
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The best answer here is to use all(), which is the builtin for this situation. We combine this with a generator expression to produce the result you want cleanly and efficiently. For example:
>>> items = [[1, 2, 0], [1, 2, 0], [1, 2, 0]]
>>...
How do I get the path to the current script with Node.js?
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So basically you can do this:
fs.readFile(path.resolve(__dirname, 'settings.json'), 'UTF-8', callback);
Use resolve() instead of concatenating with '/' or '\' else you will run into cross-platform issues.
Note: __dirname is the l...
Python division
...-100 and was having problems only to notice that even with no variables at all, this does not evaluate the way I would expect it to:
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What is the use of “assert” in Python?
...t True # nothing happens
>>> assert False
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
Assertions can include an optional message, and you can disable them when running the interpreter.
To print a message if the assertion fails:
ass...
mysql_config not found when installing mysqldb python interface
...the linux server I'm connected to via ssh. The script uses mysqldb. I have all the other components I need, but when I try to install mySQLdb via setuptools like so:,
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Assignment inside lambda expression in Python
I have a list of objects and I want to remove all objects that are empty except for one, using filter and a lambda expression.
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What is a plain English explanation of “Big O” notation?
...a notation "Θ" (which is a two-side bound). In my experience, this is actually typical of discussions in non-academic settings. Apologies for any confusion caused.
Big O complexity can be visualized with this graph:
The simplest definition I can give for Big-O notation is this:
Big-O notation is ...
Can you grab or delete between parentheses in vi/vim?
...isual mode, then you specify that you want to go 2 levels of parens up. Finally the a) selects "a block". After that you can use d or x to delete, etc.
If you don't want to include the outer parens, you can use "inner block" instead:
v2i)
See :help object-select for the complete list of related ...
How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
How do I create an average from a Ruby array?
...void integer division or your results will be wrong. Also, this isn't generally applicable to every possible element type (obviously, an average only makes sense for things that can be averaged). But if you want to go that route, use this:
class Array
def sum
inject(0.0) { |result, el| result...