大约有 13,905 项符合查询结果（耗时：0.0190秒） [XML]
if/else in a list comprehension
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You can totally do that. It's just an ordering issue:
[unicode(x.strip()) if x is not None else '' for x in row]
In general,
[f(x) if condition else g(x) for x in sequence]
And, for list comprehensions with if conditions only,
[f(x) for x in sequence if condition]
Note that this ...
Fastest way to find second (third…) highest/lowest value in vector or column
R offers max and min, but I do not see a really fast way to find another value in the order, apart from sorting the whole vector and then picking a value x from this vector.
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Replacing NAs with latest non-NA value
...ke to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
...
Why doesn't Python have a sign function?
...ed behavior for edge cases - which sometimes might require the call to cmp(x,0).
I don't know why it's not a built-in, but I have some thoughts.
copysign(x,y):
Return x with the sign of y.
Most importantly, copysign is a superset of sign! Calling copysign with x=1 is the same as a sign functi...
How can I use numpy.correlate to do autocorrelation?
...n should be the highest because the signal is identical to itself, so you expected that the first element in the autocorrelation result array would be the greatest. However, the correlation is not starting at a time difference of 0. It starts at a negative time difference, closes to 0, and then goes...
Find object in list that has attribute equal to some value (that meets any condition)
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next((x for x in test_list if x.value == value), None)
This gets the first item from the list that matches the condition, and returns None if no item matches. It's my preferred single-expression form.
However,
for x in test_li...
Max return value if empty query
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int maxShoeSize = Workers.Where(x => x.CompanyId == 8)
.Select(x => x.ShoeSize)
.DefaultIfEmpty(0)
.Max();
The zero in DefaultIfEmpty is not necessa...
How do you rotate a two dimensional array?
Inspired by Raymond Chen's post , say you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.
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图表组件 · App Inventor 2 中文网
...饼图不适用）。
高度
设置图表的垂直高度，以像素px为单位。
高度百分比
设置图表的垂直高度相对于整个屏幕高度的百分比。
标签列表
将图表的 x 轴标签更改为指定的列表，如果图表类型设置为带轴图表。
列表...
Markup XML解析库下载（Markup.h 和 Markup.cpp） - 源码下载 - 清泛网 - 专注C/C++及内核技术
Markup XML解析库下载（Markup.h 和 Markup.cpp）Markup CMarkup XML解析C++编写的，一个 h，一个 cpp，绿色小巧，直接加入工程源码编译，跨平台。使用方法参见《C++ 读写xml方法整理（持续更新）》Markup h M C++编写的，一个.h，一个.cpp，...