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How to delete (not cut) in Vim?
...
Use the "black hole register", "_ to really delete something: "_d.
Use "_dP to paste something and keep it available for further pasting.
For the second question, you could use <C-o>dw. <C-o> is used to execute a normal command without leaving ...
Dictionaries and default values
...collections import defaultdict
a = defaultdict(lambda: "default", key="some_value")
a["blabla"] => "default"
a["key"] => "some_value"
You can pass any ordinary function instead of lambda:
from collections import defaultdict
def a():
return 4
b = defaultdict(a, key="some_value")
b['absent...
Removing duplicate objects with Underscore for Javascript
...t = [{a:1,b:5},{a:1,c:5},{a:2},{a:3},{a:4},{a:3},{a:2}];
var uniqueList = _.uniq(list, function(item, key, a) {
return item.a;
});
// uniqueList = [Object {a=1, b=5}, Object {a=2}, Object {a=3}, Object {a=4}]
Notes:
Callback return value used for comparison
First comparison object with un...
Comparing two NumPy arrays for equality, element-wise
... or simply want to be safe: use one of the specialized functions:
np.array_equal(A,B) # test if same shape, same elements values
np.array_equiv(A,B) # test if broadcastable shape, same elements values
np.allclose(A,B,...) # test if same shape, elements have close enough values
...
Programmatically generate video or animated GIF in Python?
...longer movies, use the streaming approach:
import imageio
with imageio.get_writer('/path/to/movie.gif', mode='I') as writer:
for filename in filenames:
image = imageio.imread(filename)
writer.append_data(image)
...
Why does “pip install” inside Python raise a SyntaxError?
...stalled package so this is the right way of using the API: subprocess.check_call([sys.executable, '-m', 'pip', 'install', 'SomeProject']) but since Python allows to access internal API and you know what you're using the API for you may want to use internal API anyway eg. if you're building own GUI p...
Printf width specifier to maintain precision of floating-point value
...be to print one seventh as in:
#include <float.h>
int Digs = DECIMAL_DIG;
double OneSeventh = 1.0/7.0;
printf("%.*e\n", Digs, OneSeventh);
// 1.428571428571428492127e-01
But let's dig deeper ...
Mathematically, the answer is "0.142857 142857 142857 ...", but we are using finite precision...
App Inventor 2 实现上传文件到服务器全方案总结 · App Inventor 2 中文网
...
php服务端代码参考：
python服务端参考：
from flask_restful import Api, Resource
from flask import Flask, request
app = Flask(__name__)
api = Api(app)
# 这边的类名是自己定义的
class receive_pic(Resource):
def put(self):
#接收二进制流保存为图...
Node.js get file extension
...inted out, and not write your own. More info: nodejs.org/api/path.html#path_path_extname_p
– xentek
Feb 23 '14 at 6:20
...
What belongs in an educational tool to demonstrate the unwarranted assumptions people make in C/C++?
...)<sizeof(int)' is false.
..22 floating point is always IEEE
but 'STDC_IEC_559_is_defined' is false.
..25 pointer arithmetic works outside arrays
but '(diff=&var.int2-&var.int1, &var.int1+diff==&var.int2)' is false.
From what I can say with my puny test cases, you are Stop at...