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How to join (merge) data frames (inner, outer, left, right)
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There is the data.table approach for an inner join, which is very time and memory efficient (and necessary for some larger data.frames):
library(data.table)
dt1 <- data.table(df1, key = "CustomerId")
dt2 <- data.table(df2, key = "CustomerId")
joined.dt1.dt.2 <- dt1[dt2]
merge...
When should the volatile keyword be used in C#?
...cks guarantee
that only one thread accesses a given chunk of memory at a time, and so
on. The number of situations in which a lock is too slow is very
small, and the probability that you are going to get the code wrong
because you don't understand the exact memory model is very large. I
do...
How to fix “ImportError: No module named …” error in Python?
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Thanks and yes, I had __init__.py. The problem this time was with $PYTHONPATH. Ignacio's solution worked.
– bodacydo
Feb 24 '10 at 13:08
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Print string to text file
I'm using Python to open a text document:
5 Answers
5
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What is the simplest way to convert a Java string from all caps (words separated by underscores) to
The title pretty much says it all. What's the simplest/most elegant way that I can convert, in Java, a string from the format "THIS_IS_AN_EXAMPLE_STRING" to the format " ThisIsAnExampleString "? I figure there must be at least one way to do it using String.replaceAll() and a regex.
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Referring to a Column Alias in a WHERE Clause
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9 Answers
9
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How do you embed binary data in XML?
... Wow. This will make the average kilobyte-range file about 230 times larger :)
– Nyerguds
Aug 8 '11 at 12:03
36
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NSLog the method name with Objective-C in iPhone
Currently, we are defining ourselves an extended log mechanism to print out the class name and the source line number of the log.
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How can I sanitize user input with PHP?
...u can't generically filter data without any context of what it's for. Sometimes you'd want to take a SQL query as input and sometimes you'd want to take HTML as input.
You need to filter input on a whitelist -- ensure that the data matches some specification of what you expect. Then you need to e...
In Subversion can I be a user other than my login name?
...u need to login like the above once and you are all set for the subsequent times(Unless you restart your machine).
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