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Flattening a shallow list in Python [duplicate]
...st of iterables with a list comprehension, or failing that, what would you all consider to be the best way to flatten a shallow list like this, balancing performance and readability?
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How do I correctly clean up a Python object?
...it close() statement is that you have to worry about people forgetting to call it at all or forgetting to place it in a finally block to prevent a resource leak when an exception occurs.
To use the with statement, create a class with the following methods:
def __enter__(self)
def __exit__(self...
What is the most pythonic way to check if an object is a number?
...and is not iterable" could be a good definition in some cases. But,
you really need to ask yourself, what it is that you're asking that what you want to consider "a number" must definitely be able to do, and what it must absolutely be unable to do -- and check.
This may also be needed in 2.6 or la...
Is there a TRY CATCH command in Bash
... writing a shell script and need to check that a terminal app has been installed. I want to use a TRY/CATCH command to do this unless there is a neater way.
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What is a clean, pythonic way to have multiple constructors in Python?
...
Actually None is much better for "magic" values:
class Cheese():
def __init__(self, num_holes = None):
if num_holes is None:
...
Now if you want complete freedom of adding more parameters:
class Cheese...
How to add property to a class dynamically?
...ing on. Better late than never.
You can add a property to a class dynamically. But that's the catch: you have to add it to the class.
>>> class Foo(object):
... pass
...
>>> foo = Foo()
>>> foo.a = 3
>>> Foo.b = property(lambda self: self.a + 1)
>>&...
Which characters are valid in CSS class names/selectors?
What characters/symbols are allowed within the CSS class selectors?
I know that the following characters are invalid , but what characters are valid ?
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Reimport a module in python while interactive
... Redefinitions of names will override the old definitions, so this is generally not a problem, but if the new version of a module does not define a name that was defined by the old version, the old definition is not removed.
If a module imports objects from another module using from ... import ..., ...
Python __str__ versus __unicode__
...onfusing, but in 2.x we're stuck with them for compatibility reasons. Generally, you should put all your string formatting in __unicode__(), and create a stub __str__() method:
def __str__(self):
return unicode(self).encode('utf-8')
In 3.0, str contains characters, so the same methods are nam...
How to find out which package version is loaded in R?
... figuring out how to use my university cluster. It has 2 versions of R installed. System wide R 2.11 (Debian 6.0) and R 2.14.2 in non-standard location.
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