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List comprehension vs map
...and most (not all) pythonistas consider them more direct and clearer.
An example of the tiny speed advantage of map when using exactly the same function:
$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x ...
What are the differences between “=” and “
... differences between the assignment operators = and <- in R?
As your example shows, = and <- have slightly different operator precedence (which determines the order of evaluation when they are mixed in the same expression). In fact, ?Syntax in R gives the following operator precedence table,...
Using npm behind corporate proxy .pac
I need to download several packages through npm but our corporate proxy configuration is a .pac file (i'm on windows)
25 An...
In WPF, what are the differences between the x:Name and Name attributes?
The title says it all. Sometimes it seems that the Name and x:Name attributes are interchangeable.
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Why is there no xrange function in Python3?
Recently I started using Python3 and it's lack of xrange hurts.
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6
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Add regression line equation and R^2 on graph
...S STRING
# SOURCE: https://groups.google.com/forum/#!topic/ggplot2/1TgH-kG5XMA
lm_eqn <- function(df){
m <- lm(y ~ x, df);
eq <- substitute(italic(y) == a + b %.% italic(x)*","~~italic(r)^2~"="~r2,
list(a = format(unname(coef(m)[1]), digits = 2),
b = format(...
Checking if all elements in a list are unique
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Not the most efficient, but straight forward and concise:
if len(x) > len(set(x)):
pass # do something
Probably won't make much of a difference for short lists.
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List comprehension on a nested list?
...w you would do this with a nested list comprehension:
[[float(y) for y in x] for x in l]
This would give you a list of lists, similar to what you started with except with floats instead of strings. If you want one flat list then you would use [float(y) for x in l for y in x].
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How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
I have two Python dictionaries, and I want to write a single expression that returns these two dictionaries, merged (i.e. taking the union). The update() method would be what I need, if it returned its result instead of modifying a dictionary in-place.
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How to evaluate a math expression given in string form?
I'm trying to write a Java routine to evaluate math expressions from String values like:
25 Answers
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