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Evaluating a mathematical expression in a string
...p://pyparsing.wikispaces.com/message/view/home/15549426
'''
__note__ = '''
All I've done is rewrap Paul McGuire's fourFn.py as a class, so I can use it
more easily in other places.
'''
class NumericStringParser(object):
'''
Most of this code comes from the fourFn.py pyparsing example
...
How can I time a code segment for testing performance with Pythons timeit?
...r if you want to average the time elapsed by several runs, you have to manually call the function multiple times (As I think you already do in you example code and timeit does automatically when you set its number argument)
import time
def myfast():
code
n = 10000
t0 = time.time()
for i in ran...
What is the documents directory (NSDocumentDirectory)?
...ath = paths.firstObject;
return basePath;
}
This Documents directory allows you to store files and subdirectories your app creates or may need.
To access files in the Library directory of your apps sandbox use (in place of paths above):
[NSSearchPathForDirectoriesInDomains(NSLibraryDirectory...
Why prefer two's complement over sign-and-magnitude for signed numbers?
...o add them.
Two's complement addition is very simple. You add numbers normally and any carry bit at the end is discarded. So they're added as follows:
0010
+ 1111
=10001
= 0001 (discard the carry)
0001 is 1, which is the expected result of "2+(-1)".
But in your "intuitive" method, adding is m...
What does a type followed by _t (underscore-t) represent?
...
As Douglas Mayle noted, it basically denotes a type name. Consequently, you would be ill-advised to end variable or function names with '_t' since it could cause some confusion. As well as size_t, the C89 standard defines wchar_t, off_t, ptrdiff_t, and p...
What is uint_fast32_t and why should it be used instead of the regular int and uint32_t?
...
int may be as small as 16 bits on some platforms. It may not be sufficient for your application.
uint32_t is not guaranteed to exist. It's an optional typedef that the implementation must provide iff it has an unsigned integer type of exactl...
Get event listeners attached to node using addEventListener
...
You can't.
The only way to get a list of all event listeners attached to a node is to intercept the listener attachment call.
DOM4 addEventListener
Says
Append an event listener to the associated list of event listeners with type set to type, listener set to ...
In which case do you use the JPA @JoinTable annotation?
... project_id
name name task_id
The Project_Tasks table is called a "Join Table". To implement this second solution in JPA you need to use the @JoinTable annotation. For example, in order to implement a uni-directional one-to-many association, we can define our entities as such:
Proj...
Can I use __init__.py to define global variables?
I want to define a constant that should be available in all of the submodules of a package. I've thought that the best place would be in in the __init__.py file of the root package. But I don't know how to do this. Suppose I have a few subpackages and each with several modules. How can I access th...
How to identify platform/compiler from preprocessor macros?
...
I'm sorry, but this answer is quite incorrect on all accounts and doesn't even answer the question.
– rubenvb
Jan 27 '15 at 20:13
...