大约有 16,000 项符合查询结果（耗时：0.0242秒） [XML]
Is it possible to get element from HashMap by its position?
...
Use a LinkedHashMap and when you need to retrieve by position, convert the values into an ArrayList.
LinkedHashMap<String,String> linkedHashMap = new LinkedHashMap<String,String>();
/* Populate */
linkedHashMap.put("key0","value0");
linkedHashMap.put("key1","value1");
linked...
Showing the stack trace from a running Python application
...'s dump). Here is an implementation based on this blog:
import threading, sys, traceback
def dumpstacks(signal, frame):
id2name = dict([(th.ident, th.name) for th in threading.enumerate()])
code = []
for threadId, stack in sys._current_frames().items():
code.append("\n# Thread:...
How to enumerate an enum
...tAllSelectedItems<T>(this Enum value)
{
int valueAsInt = Convert.ToInt32(value, CultureInfo.InvariantCulture);
foreach (object item in Enum.GetValues(typeof(T)))
{
int itemAsInt = Convert.ToInt32(item, CultureInfo.InvariantCulture);
if (ite...
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))
...
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))
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Value of type 'T' cannot be converted to
...xception, just like with any invalid cast. But I don't see why it couldn't convert to object and then to T. I agree with Triynko, although I suppose the designers had boxing/unboxing in mind.
– Fernando Gómez
May 30 '19 at 23:32
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What is an unsigned char?
...nsigned.
Now, i had a discussion with someone about what happens when you convert the value -1 of type int to unsigned char. He refused the idea that the resulting unsigned char has all its bits set to 1, because he was worried about sign representation. But he don't have to. It's immediately follo...
How do I get currency exchange rates via an API such as Google Finance? [closed]
...
Thanks for all your answers.
Free currencyconverterapi:
Rates updated every 30 min
API key is now required for the free server.
A sample conversion URL is: http://free.currencyconverterapi.com/api/v5/convert?q=EUR_USD&compact=y
For posterity here they are alon...
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...
What is cardinality in MySQL?
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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...