大约有 44,000 项符合查询结果（耗时：0.0710秒） [XML]
Dump a NumPy array into a csv file
...
I believe you can also accomplish this quite simply as follows:
Convert Numpy array into a Pandas dataframe
Save as CSV
e.g. #1:
# Libraries to import
import pandas as pd
import nump as np
#N x N numpy array (dimensions dont matter)
corr_mat #your numpy array
...
Java ArrayList how to add elements at the beginning
...optimized for adding elements at the first index. Mind though, that if you convert your collection to one of these, the conversation will probably need a time and space complexity of O(n)
Deque
The JDK includes the Deque structure which offers methods like addFirst(e) and offerFirst(e)
Deque<...
What is a lambda (function)?
...ow.FieldName > 15 );
LinqToSql can read that function (x > 15) and convert it to the actual SQL to execute using expression trees.
The statement above becomes:
select ... from [tablename]
where [FieldName] > 15 --this line was 'read' from the lambda function
This is different fr...
Java 8 stream reverse order
...t;Integer> list = Arrays.asList(1,2,3,4);
list.stream()
.boxed() // Converts Intstream to Stream<Integer>
.sorted(Collections.reverseOrder()) // Method on Stream<Integer>
.forEach(System.out::println);
...
Most common C# bitwise operations on enums
...(bit => ((flags.GetTypeCode() == TypeCode.UInt64 ? (long)(ulong)flags : Convert.ToInt64(flags)) & (1L << bit)) != 0)
.Select(bit => Enum.ToObject(flags.GetType(), 1L << bit))`
Enums.NET flags.GetFlags()
I'm trying to get these improvements incorporated into .NET Core and...
Convert timedelta to total seconds
... 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix...
Can virtual functions have default parameters?
.... However since no one mentions simple and effective solution, here it is: Convert your parameters to struct and then you can have default values to struct members!
So instead of,
//bad idea
virtual method1(int x = 0, int y = 0, int z = 0)
do this,
//good idea
struct Param1 {
int x = 0, y = 0...
Change type of varchar field to integer: “cannot be cast automatically to type integer”
...YPE integer USING (trim(col_name)::integer);
to strip white space before converting.
This shoud've been obvious from an error message if the command was run in psql, but it's possible PgAdmin-III isn't showing you the full error. Here's what happens if I test it in psql on PostgreSQL 9.2:
=> ...
I want to get Year, Month, Day, etc from Java Date to compare with Gregorian Calendar date in Java.
...
With Java 8 and later, you can convert the Date object to a LocalDate object and then easily get the year, month and day.
Date date = new Date();
LocalDate localDate = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
int year = localDate.ge...
How do I provide custom cast support for my class?
... implicit operator byte[] (MyType x)
{
byte[] ba = // put code here to convert x into a byte[]
return ba;
}
or
public static explicit operator MyType(byte[] x)
{
if (!CanConvert)
throw new DataValueNullException();
// Factory to convert byte[] x into MyType
MyType mt ...