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Getting a map() to return a list in Python 3.x
...ases, this ends up saving memory, and should make things go faster.
If all you're going to do is iterate over this list eventually, there's no need to even convert it to a list, because you can still iterate over the map object like so:
# Prints "ABCD"
for ch in map(chr,[65,66,67,68]):
prin...
What is an undefined reference/unresolved external symbol error and how do I fix it?
... token is converted into a token. (2.7). The
resulting tokens are syntactically and semantically analyzed and
translated as a translation unit. [SNIP]
Translated translation units and instantiation units are combined as follows: [SNIP]
All external entity references are resolved. Library components ...
Django dynamic model fields
...rks)
This solution is based on Entity Attribute Value data model, essentially, it uses several tables to store dynamic attributes of objects. Great parts about this solution is that it:
uses several pure and simple Django models to represent dynamic fields, which makes it simple to understand an...
Is there an expression for an infinite generator?
...
for x in iter(int, 1): pass
Two-argument iter = zero-argument callable + sentinel value
int() always returns 0
Therefore, iter(int, 1) is an infinite iterator. There are obviously a huge number of variations on this particular theme (especially once you add lambda into the mix). One va...
What is the difference between “px”, “dip”, “dp” and “sp”?
...lems with dp while everything works fine with dip
– DallaRosa
Jul 4 '11 at 6:07
255
One note abou...
Useful code which uses reduce()? [closed]
...found for it besides + and * were with and and or, but now we have any and all to replace those cases.
foldl and foldr do come up in Scheme a lot...
Here's some cute usages:
Flatten a list
Goal: turn [[1, 2, 3], [4, 5], [6, 7, 8]] into [1, 2, 3, 4, 5, 6, 7, 8].
reduce(list.__add__, [[1, 2, 3]...
How to open a URL in a new Tab using JavaScript or jQuery? [duplicate]
How to open a URL in new tab instead of new window programatically?
6 Answers
6
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MySQL, Check if a column exists in a table with SQL
...pecific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
...
How do I migrate a model out of one django app and into a new one?
... that one of these models should be in a separate app. I do have south installed for migrations, but I don't think this is something it can handle automatically. How can I migrate one of the models out of the old app into a new one?
...
Can I change the checkbox size using CSS?
...ers no solutions in many cases (no solution to firefox on xp? no chrome at all?), is outdated and only contains a link and a comment of not much value.
– nurettin
Feb 13 '13 at 15:34
...