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What Ruby IDE do you prefer? [closed]
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25 Answers
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Check if OneToOneField is None in Django
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92
To check if the (OneToOne) relation exists or not, you can use the hasattr function:
if hasattr...
How can I add numbers in a Bash script?
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For integers:
Use arithmetic expansion: $((EXPR))
num=$((num1 + num2))
num=$(($num1 + $num2)) # Also works
num=$((num1 + 2 + 3)) # ...
num=$[num1+num2] # Old, deprecated arithmetic expression syntax
Using the external expr utility. Note that this is only needed for ...
How to correctly close a feature branch in Mercurial?
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218
One way is to just leave merged feature branches open (and inactive):
$ hg up default
$ hg me...
How to find all serial devices (ttyS, ttyUSB, ..) on Linux without opening them?
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12 Answers
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R programming: How do I get Euler's number?
For example, how would I go about entering the value e^2 in R?
3 Answers
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How can I parse a time string containing milliseconds in it with python?
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327
Python 2.6 added a new strftime/strptime macro %f, which does microseconds. Not sure if this i...
Mockito. Verify method arguments
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edited Feb 19 '17 at 21:00
Nikunj Undhad
22222 silver badges66 bronze badges
answered Aug 19 '15 at...
Define a lambda expression that raises an Exception
... however allow you to conditionally raise exceptions, e.g.:
y = lambda x: 2*x if x < 10 else raise_(Exception('foobar'))
Alternatively you can raise an exception without defining a named function. All you need is a strong stomach (and 2.x for the given code):
type(lambda:0)(type((lambda:0)....
How to hide action bar before activity is created, and then show it again?
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27 Answers
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