大约有 43,700 项符合查询结果（耗时：0.0330秒） [XML]
Pandas get topmost n records within each group
...
Did you try df.groupby('id').head(2)
Ouput generated:
>>> df.groupby('id').head(2)
id value
id
1 0 1 1
1 1 2
2 3 2 1
4 2 2
3 7 3 1
4 8 4 1
(Keep in mind that you might nee...
How can you detect the version of a browser?
...
27 Answers
27
Active
...
SQL Server: Filter output of sp_who2
Under SQL Server, is there an easy way to filter the output of sp_who2? Say I wanted to just show rows for a certain database, for example.
...
What is the difference between int, Int16, Int32 and Int64?
What is the difference between int , System.Int16 , System.Int32 and System.Int64 other than their sizes?
10 Answers
...
Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
...rray. For this example let us say the array is 4x4 and I want to extract a 2x2 array from it.
7 Answers
...
nonlocal keyword in Python 2.x
I'm trying to implement a closure in Python 2.6 and I need to access a nonlocal variable but it seems like this keyword is not available in python 2.x. How should one access nonlocal variables in closures in these versions of python?
...
Ruby on Rails and Rake problems: uninitialized constant Rake::DSL
...
answered May 22 '11 at 4:11
Caley WoodsCaley Woods
4,62944 gold badges2626 silver badges3636 bronze badges
...
Write a function that returns the longest palindrome in a given string
I thought of a solution but it runs in O(n^2) time
22 Answers
22
...
xkcd style graphs in MATLAB
...plot, but you will end up with an image, not an editable plot.
I'll show #2 first, and my attempt at #1 below (if you like #1 better, look at Rody's solution!).
This solution relies on two key functions: EXPORT_FIG from the file exchange to get an anti-aliased screenshot, and IMTRANSFORM to get ...
“for loop” with two variables? [duplicate]
...
201
If you want the effect of a nested for loop, use:
import itertools
for i, j in itertools.prod...