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How do I run a Ruby file in a Rails environment?
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#!/usr/bin/env /Users/me/rails_project/script/rails runner
Product.all.each { |p| p.price *= 2 ; p.save! }
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undefined reference to boost::system::system_category() when compiling
...raries. I have the 1.46-dev Boost libraries from the Ubuntu Repository installed, but I get an error when compiling the program.
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check if variable is dataframe
...rame
Yes: isinstance(x, pd.DataFrame)
And don't even think about
if obj.__class__.__name__ = 'DataFrame':
expect_problems_some_day()
isinstance handles inheritance (see What are the differences between type() and isinstance()?). For example, it will tell you if a variable is a string (eithe...
Get selected subcommand with argparse
...s:
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('-g', '--global')
>>> subparsers = parser.add_subparsers(dest="subparser_name") # this line changed
>>> foo_parser = subparsers.add_parser('foo')
>>> foo_parser.add_argument('-c', '--count...
String formatting: % vs. .format vs. string literal
...ated. And Python, not being a lazy language, evaluates expressions before calling functions, so in your log.debug example, the expression "some debug info: %s"%some_infowill first evaluate to, e.g. "some debug info: roflcopters are active", then that string will be passed to log.debug().
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How to convert a java.util.List to a Scala list
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import scala.collection.JavaConversions._
will do implicit conversion for you; e.g.:
var list = new java.util.ArrayList[Int](1,2,3)
list.foreach{println}
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Event handling for iOS - how hitTest:withEvent: and pointInside:withEvent: are related?
...lementation of hitTest:withEvent: in UIResponder does the following:
It calls pointInside:withEvent: of self
If the return is NO, hitTest:withEvent: returns nil. the end of the story.
If the return is YES, it sends hitTest:withEvent: messages to its subviews.
it starts from the top-level subview, ...
Python Threading String Arguments
...t list
processThread.start()
If you notice, from the stack trace: self.__target(*self.__args, **self.__kwargs)
The *self.__args turns your string into a list of characters, passing them to the processLine
function. If you pass it a one element list, it will pass that element as the first argum...
Getting value of public static final field/property of a class in Java via reflection
...t(null);
Exception handling is left as an exercise for the reader.
Basically you get the field like any other via reflection, but when you call the get method you pass in a null since there is no instance to act on.
This works for all static fields, regardless of their being final. If the field ...
mfc 按钮变成了非xp风格、界面变成windows经典样式的原因总结 - C/C++ - 清...
...xp风格 xp风格stdafx.h中添加：#ifdef _UNICODE#if defined _M_IX86#pragma co...首先看一下xp风格与非xp风格：
非xp风格 xp风格
stdafx.h中添加：
#ifdef _UNICODE
#if defined _M_IX86
#pragma comment(lin...