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How to read data when some numbers contain commas as thousand separator?
...ues are expressed as strings with commas as thousand separator, e.g. "1,513" instead of 1513 . What is the simplest way to read the data into R?
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How to get the first element of an array?
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31 Answers
31
Active
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Efficient way to apply multiple filters to pandas DataFrame or Series
...'col1'] >= 1]
Out[12]:
col1 col2
1 1 11
2 2 12
In [13]: df[(df['col1'] >= 1) & (df['col1'] <=1 )]
Out[13]:
col1 col2
1 1 11
If you want to write helper functions for this, consider something along these lines:
In [14]: def b(x, col, op, n):
...
Adding 'serial' to existing column in Postgres
I have a small table (~30 rows) in my Postgres 9.0 database with an integer ID field (the primary key) which currently contains unique sequential integers starting at 1, but which was not created using the 'serial' keyword.
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How to verify that a specific method was not called using Mockito?
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1132
Even more meaningful :
import static org.mockito.Mockito.never;
import static org.mockito.Mock...
SVG gradient using CSS
...ent);
}
<svg width="100" height="50" version="1.1" xmlns="http://www.w3.org/2000/svg">
<style type="text/css">
rect{fill:url(#MyGradient)}
</style>
<defs>
<linearGradient id="MyGradient">
<stop offset="5%" stop-colo...
Take the content of a list and append it to another list
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379
You probably want
list2.extend(list1)
instead of
list2.append(list1)
Here's the differen...
Build vs new in Rails 3
In the Rails 3 docs , the build method for associations is described as being the same as the new method, but with the automatic assignment of the foreign key. Straight from the docs:
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How do you compare two version Strings in Java?
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edited Jan 12 '15 at 15:35
Balder
7,94433 gold badges3535 silver badges5757 bronze badges
answered Oct...
What is the difference between libsqlite3.dylib and libsqlite3.0.dylib?
...s yet but one of the early steps from this tutorial is linking the SQLite3 framework. The tutorial calls for libsqlite3.0.dylib but I noticed another one libsqlite3.dylib. Is the latter just a symlink to the latest v3 library like the convention for package managers on UNIX or is there a differe...