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Catching an exception while using a Python 'with' statement
... print 'oops'
If you want different handling for errors from the open call vs the working code you could do:
try:
f = open('foo.txt')
except IOError:
print('error')
else:
with f:
print f.readlines()
...
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...
If table exists drop table then create it, if it does not exist just create it
...s case than not to cover, see locking note below).
Second RENAME ... atomically replaces table definition, refer to
MySQL manual
for details.
At last, DROP ... just cleans up the old table,
obviously.
Wrapping all statements with something like SELECT GET_LOCK('__upgrade', -1); ... DO RELEASE_LOCK...
How does deriving work in Haskell?
Algebraic Data Types (ADTs) in Haskell can automatically become instances of some typeclasse s (like Show , Eq ) by deriving from them.
...
Scala: List[Future] to Future[List] disregarding failed futures
...ures to a Future of List. I'm using Playframework, so ultimately, what I really want is a Future[Result] , but to make things simpler, let's just say Future[List[Int]] The normal way to do this would be to use Future.sequence(...) but there's a twist... The list I'm given usually has around 10-...
enum - getting value of enum on string conversion
...>> member.value
1
You could add a __str__ method to your enum, if all you wanted was to provide a custom string representation:
class D(Enum):
def __str__(self):
return str(self.value)
x = 1
y = 2
Demo:
>>> from enum import Enum
>>> class D(Enum):
...
How does Django's Meta class work?
I am using Django which allows people to add extra parameters to a class by using class Meta .
6 Answers
...
Alarm Manager Example
...
Confirmed - for me alarms would not fire without the intent.
– nsandersen
Jul 27 '19 at 23:58
...
std::vector performance regression when enabling C++11
I have found an interesting performance regression in a small C++ snippet, when I enable C++11:
1 Answer
...
Getting the docstring from a function
...
On ipython or jupyter notebook, you can use all the above mentioned ways, but i go with
my_func?
or
?my_func
for quick summary of both method signature and docstring.
I avoid using
my_func??
(as commented by @rohan) for docstring and use it only to check th...