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Difference between a theta join, equijoin and natural join
... yourself).
** I don't quite know what the result of SELECT * FROM table_expression; is. I know it is not a relation because, among other reasons, it can have columns with duplicate names or a column with no name. I know it is not a set because, among other reasons, the column order is significan...
How to use a dot “.” to access members of dictionary?
...ope to help you:
class Map(dict):
"""
Example:
m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
"""
def __init__(self, *args, **kwargs):
super(Map, self).__init__(*args, **kwargs)
for arg in args:
if isinstance(arg, dict...
How to remove illegal characters from path and filenames?
...blic string ReplaceInvalidChars(string filename)
{
return string.Join("_", filename.Split(Path.GetInvalidFileNameChars()));
}
This answer was on another thread by Ceres, I really like it neat and simple.
share
...
How to sort two lists (which reference each other) in the exact same way
... of 10000 random ints): %timeit index = range(len(l1)); index.sort(key=l1.__getitem__); map(l1.__getitem__, index); map(l2.__getitem__, index) 100 loops, best of 3: 8.04 ms per loop (vs 9.17 ms, 9.07 ms for senderle's timits)
– Quantum7
Aug 12 '13 at 21:35
...
Lodash - difference between .extend() / .assign() and .merge()
...
An important difference seems to be that while _.merge returns a new merged object, _.extend mutates the destination object in-place,
– letronje
Feb 13 '15 at 9:31
...
How can I change the color of pagination dots of UIPageControl?
...ontrolDelegate;
@interface PageControl : UIView
{
@private
NSInteger _currentPage;
NSInteger _numberOfPages;
UIColor *dotColorCurrentPage;
UIColor *dotColorOtherPage;
NSObject<PageControlDelegate> *delegate;
//If ARC use __unsafe_unretained id delegate;
}
// Set thes...
Python dictionary: Get list of values for list of keys
...n list-comp:
Build list and throw exception if key not found: map(mydict.__getitem__, mykeys)
Build list with None if key not found: map(mydict.get, mykeys)
Alternatively, using operator.itemgetter can return a tuple:
from operator import itemgetter
myvalues = itemgetter(*mykeys)(mydict)
# use ...
Does MongoDB's $in clause guarantee order
...ly have two options.
So let's say that you were matching on the values of _id in your documents with an array that is going to be passed in to the $in as [ 4, 2, 8 ].
Approach using Aggregate
var list = [ 4, 2, 8 ];
db.collection.aggregate([
// Match the selected documents by "_id"
...
ARC and bridged cast
...ription is confusing. Since I just grasped them, I'll try to summarize:
(__bridge_transfer <NSType>) op or alternatively CFBridgingRelease(op) is used to consume a retain-count of a CFTypeRef while transferring it over to ARC. This could also be represented by id someObj = (__bridge <NSTy...
Meaning of @classmethod and @staticmethod for beginner? [duplicate]
...thod can have no parameters at all.
Example
class Date(object):
def __init__(self, day=0, month=0, year=0):
self.day = day
self.month = month
self.year = year
@classmethod
def from_string(cls, date_as_string):
day, month, year = map(int, date_as_string...