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What is a lambda (function)?
... closures. With that power you can do things like this.
Python
def adder(x):
return lambda y: x + y
add5 = adder(5)
add5(1)
6
As you can see from the snippet of Python, the function adder takes in an argument x, and returns an anonymous function, or lambda, that takes another argument y. Tha...
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.
15 Answers
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Why is there no xrange function in Python3?
Recently I started using Python3 and it's lack of xrange hurts.
6 Answers
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
...
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].
...
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.
...