大约有 40,000 项符合查询结果（耗时：0.0307秒） [XML]
Naming returned columns in Pandas aggregate function? [duplicate]
...er, this does not work with lambda functions, since they are anonymous and all return <lambda>, which causes a name collision:
>>> df.groupby('A').agg({'B': [lambda x: x.min(), lambda x: x.max]})
SpecificationError: Function names must be unique, found multiple named <lambda>
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Calling parent class __init__ with multiple inheritance, what's the right way?
...ing super() leads to greater flexibility for subclasses.
In the direct call approach, C.__init__ can call both A.__init__ and B.__init__.
When using super(), the classes need to be designed for cooperative multiple inheritance where C calls super, which invokes A's code which will also call supe...
Most efficient way to determine if a Lua table is empty (contains no entries)?
...olution though, and I honestly can't assume that my solution is faster overall.
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How do you express binary literals in Python?
... memory.
Note that leading zeros in a non-zero decimal number are not allowed.
This is for disambiguation with C-style octal literals, which Python
used before version 3.0.
Some examples of integer literals:
7 2147483647 0o177 0b100110111
3 7922816251...
How do I convert a String object into a Hash object?
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The string created by calling Hash#inspect can be turned back into a hash by calling eval on it. However, this requires the same to be true of all of the objects in the hash.
If I start with the hash {:a => Object.new}, then its string represen...
How to get the return value from a thread in python?
...ram in param_list] The order will be maintained, and exiting the with will allow result collection. [f.result() for f in futures]
– jayreed1
Jun 4 at 21:29
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Why does C++11 not support designated initializer lists as C99? [closed]
... named function arguments. But as of right now, name arguments don't officially exist. See N4172 Named arguments for a proposal of this. It would make code less error prone and easier to read.
– David Baird
Nov 29 '15 at 15:11
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Why is it string.join(list) instead of list.join(string)?
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I do not agree conceptually even if It makes sense codewise. list.join(string) appears more an object-oriented approach whereas string.join(list) sounds much more procedural to me.
– Eduardo Pignatelli
Jan 14 ...
Multi-statement Table Valued Function vs Inline Table Valued Function
...e compiler cannot use any table statistics on the tables in the MSTVF. So, all things being equal, (which they rarely are), the ITVF will perform better than the MSTVF. In my tests, the performance difference in completion time was negligible however from a statistics standpoint, it was noticeable.
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What is context in _.each(list, iterator, [context])?
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The context lets you provide arguments at call-time, allowing easy customization of generic pre-built helper functions.
some examples:
// stock footage:
function addTo(x){ "use strict"; return x + this; }
function pluck(x){ "use strict"; return x[this]; }
function l...