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add column to mysql table if it does not exist
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OK this is really crude but someone's got to say it. if you are simply running a SQL script from the command line, you can give mysql the --force switch, which means keep going even if there's an error. then, just go for it. you just want...
Where in a virtualenv does the custom code go?
... instance, if I were building a WSGI application and created a virtualenv called foobar I would start with a directory structure like:
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Eclipse returns error message “Java was started but returned exit code = 1”
... message points to a problem with your Java version. Do you have a JDK installed?
Try adding the following (noting the new line):
/!\ make sure, that the -vm option occurs before the -vmargs command.
Everything after -vmargs is passed directly to the JVM.
-vm
c:/wherever/java/jdk1.6.0_21/...
Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
How to Update Multiple Array Elements in mongodb
...At this moment it is not possible to use the positional operator to update all items in an array. See JIRA http://jira.mongodb.org/browse/SERVER-1243
As a work around you can:
Update each item individually
(events.0.handled events.1.handled
...) or...
Read the document, do the edits
manually and ...
How can I use threading in Python?
...ticle/blog post that you should definitely check out (no affiliation) - Parallelism in one line: A Better Model for Day to Day Threading Tasks. I'll summarize below - it ends up being just a few lines of code:
from multiprocessing.dummy import Pool as ThreadPool
pool = ThreadPool(4)
results = pool.m...
How do you query for “is not null” in Mongo?
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This will return all documents with a key called "IMAGE URL", but they may still have a null value.
db.mycollection.find({"IMAGE URL":{$exists:true}});
This will return all documents with both a key called "IMAGE URL" and a non-null value.
d...
java get file size efficiently
...97.044
URL sum: 95534, per Iteration: 382.136
File must be caching the calls to the filesystem, while channels and URL have some overhead.
Code:
import java.io.*;
import java.net.*;
import java.util.*;
public enum FileSizeBench {
LENGTH {
@Override
public long getResult() ...
How to request Administrator access inside a batch file
...s method doesn't forward arguments. Do you know How that can be done? Basically what I observe is that on the first line %1 has some value and on the last line %1 is null. I need to forward the arguments.
– prongs
Jan 11 '13 at 11:54
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Removing Data From ElasticSearch
...lasticSearch. I have deleted my indexes. However, that doesn't seem to actually remove the data itself. The other stuff I've seen points to the Delete by Query feature. However, I'm not even sure what to query on. I know my indexes. Essentially, I'd like to figure out how to do a
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