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How are feature_importances in RandomForestClassifier determined?
...d in [1] (often cited, but unfortunately rarely read...). It is sometimes called "gini importance" or "mean decrease impurity" and is defined as the total decrease in node impurity (weighted by the probability of reaching that node (which is approximated by the proportion of samples reaching that no...
Can I have an IF block in DOS batch file?
...t, and the opening parenthesis.
I am setting @echo off to keep from seeing all of the statements printed to the console as they execute, and instead just see the output of those that specifically begin with echo.
I'm using the built-in ERRORLEVEL variable just as a test. Read more here
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How do I check if there are duplicates in a flat list?
...
Use set() to remove duplicates if all values are hashable:
>>> your_list = ['one', 'two', 'one']
>>> len(your_list) != len(set(your_list))
True
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How can I use threading in Python?
...ticle/blog post that you should definitely check out (no affiliation) - Parallelism in one line: A Better Model for Day to Day Threading Tasks. I'll summarize below - it ends up being just a few lines of code:
from multiprocessing.dummy import Pool as ThreadPool
pool = ThreadPool(4)
results = pool.m...
How to know if an object has an attribute in Python
...n is that, if the property is likely to be there most of the time, simply call it and either let the exception propagate, or trap it with a try/except block. This will likely be faster than hasattr. If the property is likely to not be there most of the time, or you're not sure, using hasattr will pr...
What is the use of “assert” in Python?
...t True # nothing happens
>>> assert False
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AssertionError
Assertions can include an optional message, and you can disable them when running the interpreter.
To print a message if the assertion fails:
ass...
How to make a Java Generic method static?
...urn value always introduce (declare) a new generic type variable.
Additionally, type variables between types (ArrayUtils) and static methods (appendToArray) never interfere with each other.
So, what does this mean:
In my answer <E> would hide the E from ArrayUtils<E> if the method woul...
How to limit the amount of concurrent async I/O operations?
... Stephen Toub, but the less announced news is that the async semaphore actually made it into the Beta release of .NET 4.5
If you look at our beloved SemaphoreSlim class (which you should be using since it's more performant than the original Semaphore), it now boasts the WaitAsync(...) series of ove...
Correct way to write line to file?
...ing files opened in text mode (the default); use a single '\n' instead, on all platforms.
Some useful reading:
The with statement
open()
'a' is for append, or use
'w' to write with truncation
os (particularly os.linesep)
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How to count total lines changed by a specific author in a Git repository?
...--author="<authorname>" --oneline --shortstat
This gives stats for all commits on the current HEAD. If you want to add up stats in other branches you will have to supply them as arguments to git log.
For passing to a script, removing even the "oneline" format can be done with an empty log f...