大约有 43,100 项符合查询结果（耗时：0.0285秒） [XML]
Why are dates calculated from January 1st, 1970?
Is there any reason behind using date(January 1st, 1970) as default standard for time manipulation? I have seen this standard in Java as well as in Python. These two languages I am aware of. Are there other popular languages which follows the same standard?
...
In-memory size of a Python structure
...
146
The recommendation from an earlier question on this was to use sys.getsizeof(), quoting:
>...
Inline labels in Matplotlib
...
mask = (xy[:,0] >= 0) & (xy[:,0] < N) & (xy[:,1] >= 0) & (xy[:,1] < N)
xy = xy[mask]
# add to pop
for p in xy:
pop[l][tuple(p)] = 1.0
# find whitespace, nice place for labels
ws = 1.0 - (np.sum(pop, axis=0) > 0) *...
CMake使用教程 - C/C++ - 清泛网 - 专注C/C++及内核技术
...它编译的，感兴趣的可以试用一下。
准备活动：
（1）安装cmake。
下载地址：http://www.cmake.org/cmake/resources/software.html
根据自己的需要下载相应的包即可，Windows下可以下载zip压缩的绿色版本，还可以下载源代码。
（2）运...
Reverse Range in Swift
...
185
Update For latest Swift 3 (still works in Swift 4)
You can use the reversed() method on a ran...
Latest jQuery version on Google's CDN
...
182
UPDATE 7/3/2014: As of now, jquery-latest.js is no longer being updated.
From the jQuery blog:...
How to determine if a decimal/double is an integer?
...
14 Answers
14
Active
...
Why does installing Nokogiri on Mac OS fail with libiconv is missing?
I've been trying to install Nokogiri on Mac OS 10.9.3 and whatever I try, the install fails in the end with the following error message:
...
how do I insert a column at a specific column index in pandas?
... the beginning
df.insert(loc, column, value)
df = pd.DataFrame({'B': [1, 2, 3], 'C': [4, 5, 6]})
df
Out:
B C
0 1 4
1 2 5
2 3 6
idx = 0
new_col = [7, 8, 9] # can be a list, a Series, an array or a scalar
df.insert(loc=idx, column='A', value=new_col)
df
Out:
A B C
0 7 1 ...