大约有 16,000 项符合查询结果（耗时：0.0159秒） [XML]
Why does Python use 'magic methods'?
...those operations that
were generic for a group of types and
which were intended to work even for
objects that didn’t have methods at
all (e.g. tuples). It is also
convenient to have a function that can
readily be applied to an amorphous
collection of objects when you use the
functi...
Using print statements only to debug
...le log methods, debug, info, warning, error and critical.
import logging, sys
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)
logging.debug('A debug message!')
logging.info('We processed %d records', len(processed_records))
...
What is Type-safe?
... call it like this:
Sum = AddTwoNumbers(5, "5");
Javascript automaticly converts the 5 to a string, and returns "55". This is due to javascript using the + sign for string concatenation. To make it type-aware, you would need to do something like:
function AddTwoNumbers(a, b)
{
return Number(...
How do I reverse an int array in Java?
...t[]>, containing one element. There is AFAICS no simple built-in way to convert an int[] to an Integer[].
– Martin Rust
Sep 22 '16 at 7:14
4
...
Using comparison operators in Scala's pattern matching system
...and a boolean expression after the pattern:
a match {
case 10 => println("ten")
case x if x > 10 => println("greater than ten")
case _ => println("less than ten")
}
Edit: Note that this is more than superficially different to putting an if after the =>, because a patter...
What is cardinality in MySQL?
...
Some columns are called high-cardinality columns because they have constraints in place (like unique) prohibiting you from putting the same value in every row.
Cardinality is a property which affects the ability to cluster, sort and search data. It is therefore an important measurement for the qu...
Show the progress of a Python multiprocessing pool imap_unordered call?
...vate attributes of the result set:
from __future__ import division
import sys
for i, _ in enumerate(p.imap_unordered(do_work, xrange(num_tasks)), 1):
sys.stderr.write('\rdone {0:%}'.format(i/num_tasks))
share
...
What is a wrapper class?
...per.stringValue();
so this is the way , we can use wrapper class type to convert into other primitive types as well. This type of conversion is used when you need to convert a primitive type to object and use them to get other primitives as well.Though for this approach , you need to write a big c...
Calendar returns wrong month [duplicate]
...treal" ) );
int month = now.getMonthValue(); // Returns 1-12 as values.
Convert legacy classes
If you have a GregorianCalendar object in hand, convert to ZonedDateTime using new toZonedDateTime method added to the old class. For more conversion info, see Convert java.util.Date to what “java.ti...
Is there a built in function for string natural sort?
...
Try this:
import re
def natural_sort(l):
convert = lambda text: int(text) if text.isdigit() else text.lower()
alphanum_key = lambda key: [ convert(c) for c in re.split('([0-9]+)', key) ]
return sorted(l, key = alphanum_key)
Output:
['elm0', 'elm1', 'Elm...