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Rails mapping array of hashes onto single hash
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163
You could compose Enumerable#reduce and Hash#merge to accomplish what you want.
input = [{"test...
How to measure time taken between lines of code in python?
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If you want to measure CPU time, can use time.process_time() for Python 3.3 and above:
import time
start = time.process_time()
# your code here
print(time.process_time() - start)
First call turns the timer on, and second call tells you how many seconds have elapsed.
There is also a functi...
Return first N key:value pairs from dict
...t(islice(iterable, n))
See it working online: ideone
Update for Python 3.6
n_items = take(n, d.items())
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switch() statement usage
...e) {
switch(type,
mean = 1,
median = 2,
trimmed = 3)
}
test2 <- function(type) {
if (type == "mean") 1
else if (type == "median") 2
else if (type == "trimmed") 3
}
system.time( for(i in 1:1e6) test1('mean') ) # 0.89 secs
system.time( for(i in 1:1e6) test2('mean') ) #...
Remove rows with duplicate indices (Pandas DataFrame and TimeSeries)
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I would suggest using the duplicated method on the Pandas Index itself:
df3 = df3[~df3.index.duplicated(keep='first')]
While all the other methods work, the currently accepted answer is by far the least performant for the provided example. Furthermore, while the groupby method is only slightly les...
Remove an item from a dictionary when its key is unknown
...not do what you want:
>>> some_dict = {1: "Hello", 2: "Goodbye", 3: "You say yes", 4: "I say no"}
>>> value_to_remove = "You say yes"
>>> some_dict = {key: value for key, value in some_dict.items() if value is not value_to_remove}
>>> some_dict
{1: 'Hello', 2: 'G...
Is log(n!) = Θ(n·log(n))?
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307
Remember that
log(n!) = log(1) + log(2) + ... + log(n-1) + log(n)
You can get the upper bo...
How does Python manage int and long?
...ns back. Before that it was possible to overflow an int through math ops.
3.x has further advanced this by eliminating long altogether and only having int.
Python 2: sys.maxint contains the maximum value a Python int can hold.
On a 64-bit Python 2.7, the size is 24 bytes. Check with sys.getsize...
Java 8: Where is TriFunction (and kin) in java.util.function? Or what is the alternative?
.... So if you like to see what the functions return for y := 1, y := 2, y := 3 you
have to write f(1,1) , f(1,2) , f(1,3).
In Java 8, constructive functions should be handled (most of the time) by using method references because there's not much advantage of using a constructive lambda function. The...
Wrapping null-returning method in Java with Option in Scala?
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183
The Option companion object's apply method serves as a conversion function from nullable referen...