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How to modify a global variable within a function in bash?
...(...) construct), you are creating a subshell. Subshells inherit variables from their parent shells, but this only works one way - a subshell cannot modify the environment of its parent shell. Your variable e is set within a subshell, but not the parent shell. There are two ways to pass values from ...
Is there a Python caching library?
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From Python 3.2 you can use the decorator @lru_cache from the functools library.
It's a Last Recently Used cache, so there is no expiration time for the items in it, but as a fast hack it's very useful.
from functools import...
How can I copy data from one column to another in the same table?
Is it possible to copy data from column A to column B for all records in a table in SQL?
3 Answers
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load and execute order of scripts
...r, then it would have to be coded in by registering for load notifications from the async scripts and manually sequencing javascript calls when the appropriate things are loaded.
When a script tag is inserted dynamically, how the execution order behaves will depend upon the browser. You can see ho...
How can I get a resource content from a static context?
I want to read strings from an xml file before I do much of anything else like setText on widgets, so how can I do that without an activity object to call getResources() on?
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Can modules have properties the same way that objects can?
...anybody else try this? When I put this code in one file x.py and import it from another, then calling x.y results in AttributeError: 'NoneType' object has no attribute 'c', since _M somehow has value None...
– Stephan202
May 19 '09 at 1:35
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Tool for generating railroad diagram used on json.org [closed]
...enerator. It creates SVG syntax diagrams, also known as railroad diagrams, from context-free grammars specified in EBNF. You can copy the SVG code or take screen shots.
You have to type in the grammar and it'll make the diagram.
For example, to create the first railroad diagram you show, you would...
Explaining Python's '__enter__' and '__exit__'
...plained above, use this object with the with statement (you may need to do from __future__ import with_statement at the top of the file if you're on Python 2.5).
with DatabaseConnection() as mydbconn:
# do stuff
PEP343 -- The 'with' statement' has a nice writeup as well.
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Sync data between Android App and webserver [closed]
...tent Storage:
This is how your phone actually stores the data it receives from the webserver. One possible method for accomplishing this is writing your own custom ContentProvider backed by a Sqlite database. A decent tutorial for a content provider can be found here: http://thinkandroid.wordpress....
Multiple returns from a function
...t in str_replace, $matches in preg_match). This might feel quite different from returning multiple values, but it is worth at least knowing about.
A third method is to use an object to hold the different values you need. This is more typing, so it's not used quite as often as the two methods above....