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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...
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
...
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...
Running single test from unittest.TestCase via command line
... @TomSwirly Can't check now but I think you can do it by creatiing (empty) __init__.py inside that direcrory (and subdirs, if any) and calling eg. python test/testMyCase.py test.MyCase.testItIsHot.
– Alois Mahdal
Oct 22 '15 at 19:27
...
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)
...
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...
Add spaces before Capital Letters
...xt[i + 1]) helps with acronyms with special characters and digits (i.e. ABC_DEF wont get split as AB C_DEF).
– HeXanon
Oct 3 '18 at 8:33
1
...
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...
Check if a JavaScript string is a URL
...{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address
'(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*'+ // port and path
'(\\?[;&a-z\\d%_.~+=-]*)?'+ // query string
'(\\#[-a-z\\d_]*)?$','i'); // fragment locator
return !!pattern.test(str);
}
...