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How to succinctly write a formula with many variables from a data frame?
Suppose I have a response variable and a data containing three covariates (as a toy example):
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Get difference between two lists
I have two lists in Python, like these:
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Best Practices for Laravel 4 Helpers and Basic Functions?
I'm trying to understand the best place to put a global function in Laravel 4. For example, date formatting. I don't think making a facade is worth it as facades are too modular. I've read articles about creating a library folder and storing classes there but that also seems like a lot for a simple ...
Sort a list by multiple attributes?
... = sorted(s, key = lambda x: (x[1], x[2]))
Or you can achieve the same using itemgetter (which is faster and avoids a Python function call):
import operator
s = sorted(s, key = operator.itemgetter(1, 2))
And notice that here you can use sort instead of using sorted and then reassigning:
s.sort...
Find an element in a list of tuples
...st want the first number to match you can do it like this:
[item for item in a if item[0] == 1]
If you are just searching for tuples with 1 in them:
[item for item in a if 1 in item]
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Accessing class variables from a list comprehension in the class definition
How do you access other class variables from a list comprehension within the class definition? The following works in Python 2 but fails in Python 3:
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How do exceptions work (behind the scenes) in c++
I keep seeing people say that exceptions are slow, but I never see any proof. So, instead of asking if they are, I will ask how do exceptions work behind the scenes, so I can make decisions of when to use them and whether they are slow.
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Summarizing multiple columns with dplyr? [duplicate]
I'm struggling a bit with the dplyr-syntax. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
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How to add an integer to each element in a list?
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new_list = [x+1 for x in my_list]
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