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E731 do not assign a lambda expression, use a def
I get this pep8 warning whenever I use lambda expressions. Are lambda expressions not recommended? If not why?
4 Answers
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Bad value X-UA-Compatible for attribute http-equiv on element meta
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Either X-UA-Compatible is not "standard" HTML (FSVO "standard" that involves appearing on a publicly editable wiki page referenced by the specification) or the Validator isn't up to date with the current status of that wiki.
At the...
When is “i += x” different from “i = i + x” in Python?
... depends entirely on the object i.
+= calls the __iadd__ method (if it exists -- falling back on __add__ if it doesn't exist) whereas + calls the __add__ method1 or the __radd__ method in a few cases2.
From an API perspective, __iadd__ is supposed to be used for modifying mutable objects in pl...
Selecting only numeric columns from a data frame
...e is a list we can use the list-apply functions:
nums <- unlist(lapply(x, is.numeric))
Then standard subsetting
x[ , nums]
## don't use sapply, even though it's less code
## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numer...
Fast check for NaN in NumPy
...astest way to check for the occurrence of NaN ( np.nan ) in a NumPy array X . np.isnan(X) is out of the question, since it builds a boolean array of shape X.shape , which is potentially gigantic.
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Is there a way to perform “if” in python's lambda
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The syntax you're looking for:
lambda x: True if x % 2 == 0 else False
But you can't use print or raise in a lambda.
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impr...
6个变态的C语言Hello World程序 - 创意 - 清泛网 - 专注C/C++及内核技术
...#define _(a) ________(a);
#define ______ _______(){
#define __ ______ _(0x48)_(0x65)_(0x6C)_(0x6C)
#define ___ _(0x6F)_(0x2C)_(0x20)_(0x77)_(0x6F)
#define ____ _(0x72)_(0x6C)_(0x64)_(0x21)
#define _____ __ ___ ____ _________
#include<stdio.h>
_____
hello2.c
#include<stdio.h>
main(){...
Calculate the center point of multiple latitude/longitude coordinate pairs
...ion on SO asked about finding the average of a set of compass angles.
An expansion of the approach recommended there for spherical coordinates would be:
Convert each lat/long pair into a unit-length 3D vector.
Sum each of those vectors
Normalise the resulting vector
Convert back to spherical coor...
Convert string to a variable name
...
assign is what you are looking for.
assign("x", 5)
x
[1] 5
but buyer beware.
See R FAQ 7.21
http://cran.r-project.org/doc/FAQ/R-FAQ.html#How-can-I-turn-a-string-into-a-variable_003f
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StringIO in Python3
...se
io.StringIO and it works, but I can't use it with numpy 's genfromtxt like this:
8 Answers
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