大约有 30,000 项符合查询结果（耗时：0.0420秒） [XML]
What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...target interface. In other words: the type is not changed, but the compile-time type is.
When the source object does not implement the target interface, the source object is converted into an object that implements the target interface. So both the type and the compile-time type are changed.
Let ...
Generating random number between 1 and 10 in Bash Shell Script [duplicate]
...
@ads20000 The docs say so, man bash, "Each time this parameter is referenced, a random integer between 0 and 32767 is generated." Note that this is not a bash error, it's an error of the implementer. Assuming bash implemented $RANDOM correctly, there should be a fai...
Profiling Vim startup time
...
If you're using Vim 7.2.269 or later, then there's the --startuptime option you can use.
vim --startuptime vim.log
from the help (vim -h):
--startuptime <file> Write startup timing messages to <file>
...
java.sql.SQLException: - ORA-01000: maximum open cursors exceeded
...nsactions. A connection can have only a single transaction open at any one time (but transactions can be nested)
A JDBC ResultSet is supported by a single cursor on the database. When close() is called on the ResultSet, the cursor is released.
A JDBC CallableStatement invokes a stored procedure on t...
What is the curiously recurring template pattern (CRTP)?
...xample. If you use virtual method the program will know what execute in runtime. Implementing CRTP the compiler is which decide in compile time!!! This is a great performance!
template <class T>
class Writer
{
public:
Writer() { }
~Writer() { }
void write(const char* str) con...
How to import data from mongodb to pandas?
...
I tried Monary, but it is taking a lot of time. Am I missing some optimization? Tried client = Monary(host, 27017, database="db_tmp") columns = ["col1", "col2"] data_type = ["int64", "int64"] arrays = client.query("db_tmp", "coll", {}, columns, data_type) For 5...
How to modify list entries during for loop?
...has resulted in errors in my code that I had to debug for a long period of time. Python Tutorial doesn't even mention it. Though there must be some reason to it?
– xji
Jan 29 '17 at 17:25
...
Perform commands over ssh with Python
...
As a long-time user of Paramiko (but not an expert), I can suggest using Paramiko but you should consider your use cases and how much you're willing to learn. Paramiko is very low-level, and you can easily fall into a trap where you cr...
Cannot kill Python script with Ctrl-C
...eads are destroyed instantly. So let's keep the main thread alive:
import time
while True:
time.sleep(1)
Now it will keep print 'first' and 'second' until you hit Ctrl+C.
Edit: as commenters have pointed out, the daemon threads may not get a chance to clean up things like temporary files. If...
Differences between socket.io and websockets
...ole.error('websocket connection');
for (var t = 0; t < 3; t++)
setTimeout(() => s.send('message from server', ()=>{}), 1000*t);
});
app.listen(3001, () => console.error('listening on http://localhost:3001/'));
console.error('websocket example');
Source: https://github.com/rsp/nod...