大约有 11,400 项符合查询结果（耗时：0.0351秒） [XML]
How do I get the row count of a pandas DataFrame?
I'm trying to get the number of rows of dataframe df with Pandas, and here is my code.
14 Answers
...
Matrix Transpose in Python
I am trying to create a matrix transpose function for python but I can't seem to make it work.
Say I have
18 Answers
...
Get a specific bit from byte
I have a byte, specifically one byte from a byte array which came in via UDP sent from another device. This byte stores the on/off state of 8 relays in the device.
...
How do I compare strings in Java?
I've been using the == operator in my program to compare all my strings so far.
However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.
...
Fastest way to check if a value exists in a list
...a
Clearest and fastest way to do it.
You can also consider using a set, but constructing that set from your list may take more time than faster membership testing will save. The only way to be certain is to benchmark well. (this also depends on what operations you require)
...
How to convert a string with comma-delimited items to a list in Python?
...
Like this:
>>> text = 'a,b,c'
>>> text = text.split(',')
>>> text
[ 'a', 'b', 'c' ]
Alternatively, you can use eval() if you trust the string to be safe:
>>> text = 'a,b,c'
>>> text = eval('[' + text + ']')
...
What is the significance of ProjectTypeGuids tag in the visual studio project file
...
{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC} is the GUID for C# project
{60dc8134-eba5-43b8-bcc9-bb4bc16c2548} is for project in WPF flavor package
So your ProjectTypeGuids is for a WPF C# project.
You could see the meaning of the different GUID in...
SQL Query to concatenate column values from multiple rows in Oracle
Would it be possible to construct SQL to concatenate column values from
multiple rows?
10 Answers
...
Why does dividing two int not yield the right value when assigned to double?
...
This is because you are using the integer division version of operator/, which takes 2 ints and returns an int. In order to use the double version, which returns a double, at least one of the ints must be explicitly casted to a doub...
Why does this assert throw a format exception when comparing structures?
...
I've got it. And yes, it's a bug.
The problem is that there are two levels of string.Format going on here.
The first level of formatting is something like:
string template = string.Format("Expected: {0}; Actual: {1}; Message: {2}",
...