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Plotting a list of (x, y) coordinates in python matplotlib
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x, y = zip(*li) is really elegant python code! i've been doing the more straight-forward two lines of code with a list compression on each line (like the original question)
– Trevor Boyd Smith
Aug 23 '18 at ...
Why is address zero used for the null pointer?
...emory, because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
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SQL UPDATE all values in a field with appended string CONCAT not working
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That's pretty much all you need:
mysql> select * from t;
+------+-------+
| id | data |
+------+-------+
| 1 | max |
| 2 | linda |
| 3 | sam |
| 4 | henry |
+------+-------+
4 rows in set (0.02 sec)
mysql> update t se...
SASS - use variables across multiple files
I would like to keep one central .scss file that stores all SASS variable definitions for a project.
6 Answers
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Can modules have properties the same way that objects can?
...s? 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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Rails: Default sort order for a rails model?
...ow use Book.published.confirmed.
With this method, the query is not actually executed until actual results are needed (lazy evaluation), so 7 scopes could be chained together but only resulting in 1 actual database query, to avoid performance problems from executing 7 separate queries.
You can u...
How do I make class methods / properties in Swift?
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They are called type properties and type methods and you use the class or static keywords.
class Foo {
var name: String? // instance property
static var all = [Foo]() // static type property
class var comp: In...
git: difference between “branchname” and “refs/heads/branchname”
...ee heads, remotes, and tags in your .git/refs directory, assuming you have all three types of refs in your repository.
refs/heads/0.58 specifies a branch named 0.58. If you don't specify what namespace the ref is in, git will look in the default ones. This makes using only 0.58 conceivably ambiguous...
Lock Escalation - What's happening here?
... to take fewer, larger locks (e.g. entire table) instead of locking many smaller things (e.g. row locks).
But this can be problematic when you have a huge table, because taking a lock on the entire table may lock out other queries for a long time. That's the tradeoff: many small-granularity locks...
Make the first letter uppercase inside a django template
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Using Django built-in template filter called title
{{ "myname"|title }}
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