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Is it worth using Python's re.compile?
...uick glance at the actual Python 2.5 library code, I see that Python internally compiles AND CACHES regexes whenever you use them anyway (including calls to re.match()), so you're really only changing WHEN the regex gets compiled, and shouldn't be saving much time at all - only the time it takes to ...
mongodb: insert if not exists
... has built-in support for this. Pass an extra parameter to your update() call: {upsert:true}. For example:
key = {'key':'value'}
data = {'key2':'value2', 'key3':'value3'};
coll.update(key, data, upsert=True); #In python upsert must be passed as a keyword argument
This replaces your if-find-els...
Using pip behind a proxy with CNTLM
...http://web-proxy.mydomain.com install somepackage
But exporting the https_proxy environment variable (note its https_proxy not http_proxy) did the trick:
export https_proxy=http://web-proxy.mydomain.com
then
sudo -E pip install somepackage
...
receiver type *** for instance message is a forward declaration
...
That basically means that you need to import the .h file containing the declaration of States.
However, there is a lot of other stuff wrong with your code.
You're -init'ing an object without +alloc'ing it. That won't work
You're dec...
Java Reflection: How to get the name of a variable?
...they are in scope.
Perhaps a byte-code engineering library like ASM would allow you to inspect this information at runtime. The only reasonable place I can think of for needing this information is in a development tool, and so byte-code engineering is likely to be useful for other purposes too.
...
In Python, when should I use a function instead of a method?
...sulation which is so dear to OO design.
The encapsulation principal is really what this comes down to: as a designer you should hide everything about the implementation and class internals which it is not absolutely necessarily for any user or other developer to access. Because we deal with instan...
How does BLAS get such extreme performance?
...e optimization. This boost significantly exceeds the second boost from parallelism and other hardware optimizations.
By the way, most (or even all) of the high performance BLAS implementations are NOT implemented in Fortran. ATLAS is implemented in C. GotoBLAS/OpenBLAS is implemented in C and i...
How to convert a string to lower case in Bash?
...ous ways:
POSIX standard
tr
$ echo "$a" | tr '[:upper:]' '[:lower:]'
hi all
AWK
$ echo "$a" | awk '{print tolower($0)}'
hi all
Non-POSIX
You may run into portability issues with the following examples:
Bash 4.0
$ echo "${a,,}"
hi all
sed
$ echo "$a" | sed -e 's/\(.*\)/\L\1/'
hi all
# t...
An error occurred while validating. HRESULT = '8000000A'
...t item.
We've run into this as well, and had a very unsatisfying support call on this issue with Microsoft. Long story short: it's a known issue, it won't be solved, and Microsoft advises to move away from Visual Studio Setup projects (.vdproj).
We've worked around this issue by triggering the MSI...
Difference between \w and \b regular expression meta characters
...chor like the caret and the dollar sign. It matches at a position that is called a "word boundary". This match is zero-length.
There are three different positions that qualify as word boundaries:
Before the first character in the string, if the first character is
a word character.
After the last ...
