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Flatten list of lists [duplicate]
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Sorry, I meant more readable/intuitive. Since the OP is having trouble disambiguating between what lists are (sequences of data) and how lists are represented in code (with square brackets), I highly doubt a double list comprehension will m...
When is JavaScript's eval() not evil?
...il", as used by programming language people, usually means "dangerous", or more precisely "able to cause lots of harm with a simple-looking command". So, when is it OK to use something dangerous? When you know what the danger is, and when you're taking the appropriate precautions.
To the point, let...
What's the difference between comma separated joins and join on syntax in MySQL? [duplicate]
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There is no difference at all.
Second representation makes query more readable and makes it look very clear as to which join corresponds to which condition.
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How to clone all remote branches in Git?
...from the index and created locally for you. The previous line is actually more informative as it tells you that the branch is being set up to track the remote branch, which usually means the origin/branch_name branch
Now, if you look at your local branches, this is what you'll see:
$ git branch
* e...
How to shorten my conditional statements
...e we now have the includes method, there's no point in using the ~ hack anymore. Just keeping this here for people that are interested in knowing how it works and/or have encountered it in other's code.
Instead of checking if the result of indexOf is >= 0, there is a nice little shortcut:
if (...
Iterating over every two elements in a list
...a)
for x, y in pairwise(l):
print "%d + %d = %d" % (x, y, x + y)
Or, more generally:
from itertools import izip
def grouped(iterable, n):
"s -> (s0,s1,s2,...sn-1), (sn,sn+1,sn+2,...s2n-1), (s2n,s2n+1,s2n+2,...s3n-1), ..."
return izip(*[iter(iterable)]*n)
for x, y in grouped(l, 2)...
What's the point of JAXB 2's ObjectFactory classes?
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Backward compatibility isn't the only reason. :-P
With more complicated schemas, such as ones that have complicated constraints on the values that an element's contents can take on, sometimes you need to create actual JAXBElement objects. They are not usually trivial to create by...
Removing multiple keys from a dictionary safely
... in entries:
if key in the_dict:
del the_dict[key]
A more compact version was provided by mattbornski using dict.pop()
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Constructor in an Interface?
...nterface."
"If a define a Interface for this class so that I can have more
classes which implement the message interface, I can only define the
send method and not the constructor"
...these requirements are exactly what abstract classes are for.
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What is the difference between JOIN and UNION?
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Joins and Unions can be used to combine data from one or more tables. The difference lies in how the data is combined.
In simple terms, joins combine data into new columns. If two tables are joined together, then the data from the first table is shown in one set of column alongs...