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How to initialize all members of an array to the same value?
...e same value, without multiple copy-paste, you can use macros:
#define VAL_1X 42
#define VAL_2X VAL_1X, VAL_1X
#define VAL_4X VAL_2X, VAL_2X
#define VAL_8X VAL_4X, VAL_4X
#define VAL_16X VAL_8X, VAL_8X
#define VAL_32X VAL_16X, VAL_16X
#define VAL_64X VAL_32X, VAL_32X
i...
Why use def main()? [duplicate]
...tion could be:
import sys
def main(argv):
# My code here
pass
if __name__ == "__main__":
main(sys.argv)
This means you can call main() from other scripts (or interactive shell) passing custom parameters. This might be useful in unit tests, or when batch-processing. But remember that t...
Define a lambda expression that raises an Exception
...
There is more than one way to skin a Python:
y = lambda: (_ for _ in ()).throw(Exception('foobar'))
Lambdas accept statements. Since raise ex is a statement, you could write a general purpose raiser:
def raise_(ex):
raise ex
y = lambda: raise_(Exception('foobar'))
But if...
List all the modules that are part of a python package?
...
import email
package = email
for importer, modname, ispkg in pkgutil.iter_modules(package.__path__):
print "Found submodule %s (is a package: %s)" % (modname, ispkg)
How to import them too? You can just use __import__ as normal:
import pkgutil
# this is the package we are inspecting -- for...
What is the purpose of the single underscore “_” variable in Python?
What is the meaning of _ after for in this code?
5 Answers
5
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How do I plot in real-time in a while loop using matplotlib?
...
Did not work on Win64/Anaconda matplotlib.__version__ 1.5.0. An initial figure window opened, but did not display anything, it remained in a blocked state until I closed it
– isti_spl
Feb 4 '16 at 8:39
...
Accessing class variables from a list comprehension in the class definition
...(1)]
... return Foo
...
>>> dis.dis(foo)
2 0 LOAD_BUILD_CLASS
1 LOAD_CONST 1 (<code object Foo at 0x10a436030, file "<stdin>", line 2>)
4 LOAD_CONST 2 ('Foo')
7 MAKE_FUNCTION ...
Should I use a class or dictionary?
...vantage? What happens if you later want to add some code? Where would your __init__ code go?
Classes are for bundling related data (and usually code).
Dictionaries are for storing key-value relationships, where usually the keys are all of the same type, and all the values are also of one type. Occ...
Split data frame string column into multiple columns
...
Use stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
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Dynamic instantiation from string name of a class in dynamically imported module?
...
You can use getattr
getattr(module, class_name)
to access the class. More complete code:
module = __import__(module_name)
class_ = getattr(module, class_name)
instance = class_()
As mentioned below, we may use importlib
import importlib
module = importlib.imp...