大约有 40,000 项符合查询结果（耗时：0.0420秒） [XML]
How do I check if a list is empty?
...cMahon - it's a trade-off between explicitness and type flexibility. generally, "being explicit" means not doing "magical" things. on the other hand, "duck typing" means working with more general interfaces, rather than explicitly checking for types. so something like if a == [] is forcing a part...
Multiple linear regression in Python
...as some other model evaluation criteria. If you want the stuff like in Akavall's answer, statsmodels has some more R-like diagnostics.
– djs
Mar 17 '16 at 18:56
...
Difference between RegisterStartupScript and RegisterClientScriptBlock?
...:
a. When you use RegisterStartupScript, it will render your script after all the elements in the page (right before the form's end tag). This enables the script to call or reference page elements without the possibility of it not finding them in the Page's DOM.
Here is the rendered source of the ...
Zero-pad digits in string
...
First of all, your description is misleading. Double is a floating point data type. You presumably want to pad your digits with leading zeros in a string. The following code does that:
$s = sprintf('%02d', $digit);
For more informa...
Python Dictionary Comprehension
...>> print d
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
If you want to set them all to True:
>>> d = {n: True for n in range(5)}
>>> print d
{0: True, 1: True, 2: True, 3: True, 4: True}
What you seem to be asking for is a way to set multiple keys at once on an existing dictionary. ...
Is inline assembly language slower than native C++ code?
...
Yes, most times.
First of all you start from wrong assumption that a low-level language (assembly in this case) will always produce faster code than high-level language (C++ and C in this case). It's not true. Is C code always faster than Java code? N...
What does -D_XOPEN_SOURCE do/mean?
...ch one you need (if any) by looking at the man page for each function you call.
For example, man strdup says:
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
strdup(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500
strndup(), strdupa(), strndupa():...
What are the advantages of NumPy over regular Python lists?
... Python objects, at least 4 bytes per pointer plus 16 bytes for even the smallest Python object (4 for type pointer, 4 for reference count, 4 for value -- and the memory allocators rounds up to 16). A NumPy array is an array of uniform values -- single-precision numbers takes 4 bytes each, double-pr...
How do I use the includes method in lodash to check if an object is in the collection?
...
The includes (formerly called contains and include) method compares objects by reference (or more precisely, with ===). Because the two object literals of {"b": 2} in your example represent different instances, they are not equal. Notice:
({"b": 2}...
List all base classes in a hierarchy of given class?
...ass Foo (whether it is a new-style class or not), how do you generate all the base classes - anywhere in the inheritance hierarchy - it issubclass of?
...