大约有 40,000 项符合查询结果(耗时:0.0560秒) [XML]

https://stackoverflow.com/ques... 

What Makes a Good Unit Test? [closed]

...ng lots of automated tests and that you also have run into some common pitfalls when unit testing. 18 Answers ...
https://stackoverflow.com/ques... 

How can the Euclidean distance be calculated with NumPy?

... There's a function for that in SciPy. It's called Euclidean. Example: from scipy.spatial import distance a = (1, 2, 3) b = (4, 5, 6) dst = distance.euclidean(a, b) share | ...
https://stackoverflow.com/ques... 

Why do you have to call .items() when iterating over a dictionary in Python?

...te over the same items. Implementation-wise they are different operations (__contains__ vs. __iter__). But that little inconsistency would be somewhat confusing and, well, inconsistent. share | impr...
https://stackoverflow.com/ques... 

How to unzip a file using the command line? [closed]

... it is weird,m jar actually solves the problem partially, cause it is able to list the files inside the archive and extract specified files, however, it is not possible to extract all the files at the same time... pretty weird ...
https://stackoverflow.com/ques... 

python location on mac osx

...e python on osx. I do not know if the previous owner of the laptop has installed macpython using macport. And I remembered that osx has an builtin version of python. I tried using type -a python and the result returned ...
https://stackoverflow.com/ques... 

Is there a read-only generic dictionary available in .NET?

...lt;TKey, TValue> { private readonly IDictionary<TKey, TValue> _dictionary; public ReadOnlyDictionary() { _dictionary = new Dictionary<TKey, TValue>(); } public ReadOnlyDictionary(IDictionary<TKey, TValue> dictionary) { _dictionary = dict...
https://stackoverflow.com/ques... 

std::unique_ptr with an incomplete type won't compile

... I find your first solution (adding the foo destructor) allows the class declaration itself to compile, but declaring an object of that type anywhere results in the original error ("invalid application of 'sizeof'..."). – Jeff Trull Sep 30 '1...
https://stackoverflow.com/ques... 

Difference between . and : in Lua

... To be completely precise, obj:method(1, 2, 3) is the same as do local _obj = obj _obj.method(_obj, 1, 2, 3) end Why the local variable? Because, as many have pointed out, obj:method() only indexes _ENV once to get obj. This normally just important when considering speed, but consider this s...
https://stackoverflow.com/ques... 

map vs. hash_map in C++

...tied to that key. map is implemented as a balanced binary search tree (usually a red/black tree). An unordered_map should give slightly better performance for accessing known elements of the collection, but a map will have additional useful characteristics (e.g. it is stored in sorted order, which...
https://stackoverflow.com/ques... 

Length of a JavaScript object

...an break enumerations in various libraries. Adding methods to Object is usually safe, though. Here's an update as of 2016 and widespread deployment of ES5 and beyond. For IE9+ and all other modern ES5+ capable browsers, you can use Object.keys() so the above code just becomes: var size = Object...