大约有 44,000 项符合查询结果（耗时：0.0443秒） [XML]
mysql_config not found when installing mysqldb python interface
...
mySQLdb is a python interface for mysql, but it is not mysql itself. And apparently mySQLdb needs the command 'mysql_config', so you need to install that first.
Can you confirm that you did or did not install mysql itself, by running "mysql" from the shell? That should give you a response oth...
Why does “_” (underscore) match “-” (hyphen)?
... SQL pattern matching enables you to use "_" to match any single character and "%" to match an arbitrary number of characters (including zero characters).
(From section 3.3.4.7. Pattern Matching in the MySQL documentation.)
If you want to use the underscore in like as a literal, you have to escap...
Circular list iterator in Python
...
(Loops forever, obviously)
In order to manually advance the iterator and pull values from it one by one, simply call next(pool):
>>> next(pool)
'a'
>>> next(pool)
'b'
share
|
...
How to remove from a map while iterating it?
...
The standard associative-container erase idiom:
for (auto it = m.cbegin(); it != m.cend() /* not hoisted */; /* no increment */)
{
if (must_delete)
{
m.erase(it++); // or "it = m.erase(it)" since C++11
}
else
{
...
MD5 algorithm in Objective-C
...
md5 is available on the iPhone and can be added as an addition for ie NSString and NSData like below.
MyAdditions.h
@interface NSString (MyAdditions)
- (NSString *)md5;
@end
@interface NSData (MyAdditions)
- (NSString*)md5;
@end
MyAdditions.m
#import...
python exception message capturing
... 2.x
logger.error('Failed to upload to ftp: '+ str(e))
in Python 3.x and modern versions of Python 2.x use except Exception as e instead of except Exception, e:
try:
with open(filepath,'rb') as f:
con.storbinary('STOR '+ filepath, f)
logger.info('File successfully uploaded to ...
Permutations in JavaScript?
...s into an array prior to do any permutation, so you simply remove the join and split operation
var permArr = [],
usedChars = [];
function permute(input) {
var i, ch;
for (i = 0; i < input.length; i++) {
ch = input.splice(i, 1)[0];
usedChars.push(ch);
if (input.leng...
Why does Go have a “goto” statement
...nt. I've always been taught that 'goto' statements are a thing of the past and evil for it occludes the actual flow of a program, and that functions or methods are always a better way of controlling flow.
...
Why are preprocessor macros evil and what are the alternatives?
...d encountered a phrase like "macro should never be used", "macro are evil" and so on, my question is: why? With the new C++11 is there a real alternative after so many years?
...
Updating MySQL primary key
...delete u from user_interactions u, fixit
where fixit.user_2 = u.user_2
and fixit.user_1 = u.user_1
and fixit.type = u.type
and fixit.timestamp != u.timestamp;
alter table user_interactions add primary key (user_2, user_1, type );
unlock tables;
The lock should stop further updates comi...