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What does -> mean in Python function definitions?
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And the information is available as a .__annotations__ attribute.
– Martijn Pieters♦
Jan 17 '13 at 13:06
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Bundler: Command not found
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Under uBuntu 11.04, the latest command path is now export PATH=$PATH:/var/lib/gems/1.8/bin
– Antony
Jul 16 '11 at 2:13
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Super-simple example of C# observer/observable with delegates
I recently started digging into C# but I can't by my life figure out how delegates work when implementing the observer/observable pattern in the language.
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Unable to execute dex: GC overhead limit exceeded in Eclipse
...az It depends on your OS and whether you're using a 32-bit or 64-bit JVM. If you're on a 64 bit JVM, you can safely set it to anything smaller than your RAM size minus overhead for OS/other applications. On a 32 bit VM, you'll want to keep it smaller than about 1500M (on Linux) or 1100M (on Window...
Is there any overhead to declaring a variable within a loop? (C++)
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@toto A variable like this could also be nowhere – the var variable is initialized but never used, so a reasonable optimiser can just remove it completely (except the second snippet if the variable was used somewhere after the loop).
– CiaPan...
Python: most idiomatic way to convert None to empty string?
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If you actually want your function to behave like the str() built-in, but return an empty string when the argument is None, do this:
def xstr(s):
if s is None:
return ''
return str(s)
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matplotlib does not show my drawings although I call pyplot.show()
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This answer is old, config should now be in ~/.config/matplotlib/matplotlibrc (for python 3, at least). I just had a related problem, and I think it was caused by using matplotlib in python 2.7, which created a ~/.matplotlib/ directory, and stopped python 3 f...
PHP: If internet explorer 6, 7, 8 , or 9
I want to do a conditional in PHP for the different versions of Internet Explorer along the lines of:
17 Answers
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【解决】scrapyd启动job时报错：exceptions.TypeError: __init__() got an ...
【解决】scrapyd启动job时报错：exceptions.TypeError: __init__() got an unexpected keyword argument '_job'进入项目spiders目录, 修改 spider py 文件（你自己的spider的主文件）：def __init__(self):改为：def __init__(self, *args, **kwargs):最后不要忘了重新部署一...
filter for complete cases in data.frame using dplyr (case-wise deletion)
... are a lot of variables and b) impossible when the variable names are not known (e.g. in a function that processes any data.frame).
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