大约有 42,000 项符合查询结果（耗时：0.0437秒） [XML]
Pandas DataFrame Groupby two columns and get counts
...).reset_index().groupby('col2')[[0]].max()
Out[56]:
0
col2
A 3
B 2
C 1
D 3
share
|
improve this answer
|
follow
|
...
How to read and write excel file
I want to read and write an Excel file from Java with 3 columns and N rows, printing one string in each cell. Can anyone give me simple code snippet for this? Do I need to use any external lib or does Java have built-in support for it?
...
typeof for RegExp
... |
edited Nov 27 '18 at 6:34
Alexis Wilke
14.2k77 gold badges5151 silver badges9898 bronze badges
answer...
How to split a sequence into two pieces by predicate?
...
By using partition method:
scala> List(1,2,3,4).partition(x => x % 2 == 0)
res0: (List[Int], List[Int]) = (List(2, 4),List(1, 3))
share
|
improve this answer
...
Convert bytes to a string
...
3949
You need to decode the bytes object to produce a string:
>>> b"abcde"
b'abcde'
# u...
Difference between & and && in Java? [duplicate]
...
389
& is bitwise.
&& is logical.
& evaluates both sides of the operation.
&&a...
TCP 的那些事儿（下） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...这只是一个采样，不能代表普遍情况。
经典算法
RFC793 中定义的经典算法是这样的：
1）首先，先采样RTT，记下最近好几次的RTT值。
2）然后做平滑计算SRTT（ Smoothed RTT）。公式为：（其中的 α 取值在0.8 到 0.9之间，这个...
String formatting named parameters?
...
In Python 2.6+ and Python 3, you might choose to use the newer string formatting method.
print('<a href="{0}">{0}</a>'.format(my_url))
which saves you from repeating the argument, or
print('<a href="{url}">{url}</a>'.format...
How to initialize all members of an array to the same value in Swift?
...ue like this:
With old Swift version:
var threeDoubles = [Double](count: 3, repeatedValue: 0.0)
Since Swift 3.0:
var threeDoubles = [Double](repeating: 0.0, count: 3)
which would give:
[0.0, 0.0, 0.0]
share
...
MAMP Pro 3.05 on Mavericks updated to Yosemite - Apache does not start
I have been running MAMP Pro 3.05 successfully in Yosemite up to DP4 on a partition that was a clean install of Yosemite.
1...