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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...nspect(DT))
# @0000000003B7E2A0 19 VECSXP g0c7 [OBJ,NAM(2),ATT] (len=2, tl=100)
# @00000000040C2288 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 1,2
# @00000000040C2250 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 11,12
# ATTRIB: # ..snip..
.Internal(inspect(newDT)) # precisely the same object at this p...
Convert JSON style properties names to Java CamelCase names with GSON
...
100
You can use the SerializedName annotation:
@SerializedName("field_name_in_json")
private fina...
jQuery on window resize
... ,"f50" : function(){ alert(50); }
,"f100" : function(){ alert(100); }
,"f500" : function(){ alert(500); }
,"f1000" : function(){ alert(1000);}
};
//---------------------
$(wi...
Difference between Django's annotate and aggregate methods?
... Model:
class Books(models.Model):
name = models.CharField(max_length=100)
pages = models.IntegerField()
price = models.DecimalField(max_digits=5, decimal_places=3)
In Shell:
>>> Books.objects.all().aggregate(Avg('price'))
# Above code will give the Average of the price Colu...
How can I convert a zero-terminated byte array to string?
I need to read [100]byte to transfer a bunch of string data.
13 Answers
13
...
Pandas: Setting no. of max rows
... IPython.display import display
with pd.option_context('display.max_rows', 100, 'display.max_columns', 10):
display(df) #need display to show the dataframe when using with in jupyter
#some pandas stuff
You can also reset an option back to its default value like this:
pd.reset_option('disp...
What are the use cases for selecting CHAR over VARCHAR in SQL?
...er set) storing the word "FooBar"
CHAR(6) = 6 bytes (no overhead)
VARCHAR(100) = 8 bytes (2 bytes of overhead)
CHAR(10) = 10 bytes (4 bytes of waste)
The bottom line is CHAR can be faster and more space-efficient for data of relatively the same length (within two characters length difference).
Not...
Simple way to create matrix of random numbers
...om.random_integers(low, high, shape), e.g. numpy.random.random_integers(0, 100, (3, 3))
– Pavel Anossov
Apr 9 '14 at 11:18
...
What is the best way to compute trending topics or tags?
...ay that your historical data has told you that Britney Spears usually gets 100,000 searches, and Paris Hilton usually gets 50,000. If you have a day where they both get 10,000 more searches than normal, you should be considering Paris "hotter" than Britney, because her searches increased 20% more th...
SQL WHERE ID IN (id1, id2, …, idn)
...izes like below:
Divide you list of Ids into chunks of fixed number, say 100
Chunk size should be decided based upon the memory size of your server
Suppose you have 10000 Ids, you will have 10000/100 = 100 chunks
Process one chunk at a time resulting in 100 database calls for select
Why should y...