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How to check if all of the following items are in a list?
...ems:
>>> a = {'key': 'value'}
>>> b = {'key': 'value', 'extra_key': 'extra_value'}
>>> all(item in a.items() for item in b.items())
True
>>> all(item in b.items() for item in a.items())
False
That's because dict.items returns tuples of key/value pairs, and much...
What’s the difference between “Array()” and “[]” while declaring a JavaScript array?
...re the same
d = new Array('foo', 'bar'), // c and d are arrays with 2 strings
// these are different:
e = [3] // e.length == 1, e[0] == 3
f = new Array(3), // f.length == 3, f[0] == undefined
;
Another difference is that when using new Array() you're able to set th...
Best practices for in-app database migration for Sqlite
...use prepared statements
sqlite3_exec([self database].sqliteHandle, [[NSString stringWithFormat:@"PRAGMA user_version = %d", DatabaseSchemaVersionLatest] UTF8String], NULL, NULL, NULL);
}
Here's [self database] method that lazily opens the database:
- (FMDatabase *)database {
if (!_databas...
How to unit test an object with database queries
...a, but applies to all OO-languages)
class Database {
public Result query(String query) {... real db here ...}
}
class MockDatabase extends Database {
public Result query(String query) {
return "mock result";
}
}
class ObjectThatUsesDB {
public ObjectThatUsesDB(Database db) {
this....
Print in one line dynamically
...s about this that may be surprising:
The \r goes at the beginning of the string so that, while the program is running, the cursor will always be after the number. This isn't just cosmetic: some terminal emulators get very confused if you do it the other way around.
If you don't include the last l...
Convert a Unix timestamp to time in JavaScript
...
@nickf multiplications are trivial on modern CPUs - the string concatenation will require a lot more work!
– Alnitak
Apr 19 '11 at 19:59
30
...
Method Syntax in Objective-C
...ersonData) for setting some information about person:
void setPersonData( char* name, int age, float height ) {
and in Objective-C the method would be more descriptive (setPersonName:andAge:andHeight:), like
- (void) setPersonName: (char *)name andAge:(int)age andHeight:(float)height {
...
Getting a list of files in a directory with a glob
...u can achieve this pretty easily with the help of NSPredicate, like so:
NSString *bundleRoot = [[NSBundle mainBundle] bundlePath];
NSFileManager *fm = [NSFileManager defaultManager];
NSArray *dirContents = [fm contentsOfDirectoryAtPath:bundleRoot error:nil];
NSPredicate *fltr = [NSPredicate predica...
Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
...owever, this method is affected by intermediate-object-creation as summing strings is, right?
– Dr. Jan-Philip Gehrcke
Jan 22 '15 at 21:22
6
...
bool operator ++ and --
...ntil I've done ++ often enough to cause an overflow on it's own. Even with char as the type used and CHAR_BITS something low like 5, that's 32 times before this doesn't work any more (that's still argument enough for it being a bad practice, I'm not defending the practice, just explaining why it wor...