大约有 24,000 项符合查询结果（耗时：0.0407秒） [XML]
Reading a huge .csv file
...tly over getdata() in your code:
for row in getdata(somefilename, sequence_of_criteria):
# process row
You now only hold one row in memory, instead of your thousands of lines per criterion.
yield makes a function a generator function, which means it won't do any work until you start looping ...
Temporarily disable auto_now / auto_now_add
...s:
# my model
class FooBar(models.Model):
title = models.CharField(max_length=255)
updated_at = models.DateTimeField(auto_now=True, auto_now_add=True)
# my tests
foo = FooBar.objects.get(pk=1)
# force a timestamp
lastweek = datetime.datetime.now() - datetime.timedelta(days=7)
FooBar.obj...
Replacing NAs with latest non-NA value
... = TRUE), y = sample(c(1:4, rep(NA, 4)), 20 , replace = TRUE))
dt <- dt[order(group)]
dt[, y_forward_fill := y[1], .(group, cumsum(!is.na(y)))]
dt
group y y_forward_fill
1: a NA NA
2: a NA NA
3: a NA NA
4: a 2 2
5: a ...
How do I use the includes method in lodash to check if an object is in the collection?
...e there is only one instance of {"b": 2}:
var a = {"a": 1}, b = {"b": 2};
_.includes([a, b], b);
> true
On the other hand, the where(deprecated in v4) and find methods compare objects by their properties, so they don't require reference equality. As an alternative to includes, you might want t...
Test if lists share any items in python
...
def lists_overlap3(a, b):
return bool(set(a) & set(b))
Note: the above assumes that you want a boolean as the answer. If all you need is an expression to use in an if statement, just use if set(a) & set(b):
...
Why does Javascript's regex.exec() not always return the same value? [duplicate]
... matches by performing the assignment as the loop condition.
var re = /foo_(\d+)/g,
str = "text foo_123 more text foo_456 foo_789 end text",
match,
results = [];
while (match = re.exec(str))
results.push(+match[1]);
DEMO: http://jsfiddle.net/pPW8Y/
If you don't like the placem...
Number of visitors on a specific page
... (for which I have URL).
I don't find in Analytics where to enter a URL in order to look for statistics for this specific page.
...
Get the current first responder without using a private API
...IResponder+FirstResponder.m
#import "UIResponder+FirstResponder.h"
static __weak id currentFirstResponder;
@implementation UIResponder (FirstResponder)
+(id)currentFirstResponder {
currentFirstResponder = nil;
[[UIApplication sharedApplication] sendAction:@selector(findFirstRe...
Why not inherit from List?
...football to fill in the blank:
A football team is a particular kind of _____
Did anyone say "list of football players with a few bells and whistles", or did they all say "sports team" or "club" or "organization"? Your notion that a football team is a particular kind of list of players is in y...
List columns with indexes in PostgreSQL
...um = ANY(ix.indkey)
and t.relkind = 'r'
and t.relname like 'test%'
order by
t.relname,
i.relname;
table_name | index_name | column_name
------------+------------+-------------
test | pk_test | a
test | pk_test | b
test2 | uk_test2 | b
test2 | uk_te...