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How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
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191
Use INSERT ... ON DUPLICATE KEY UPDATE. For example:
INSERT INTO `usage`
(`thing_id`, `times_...
How to replace text between quotes in vi
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183
Use ci", which means: change what inside the double quotes.
You can also manipulate other t...
what is the preferred way to mutate a React state?
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concat returns a new array, so you can do
this.setState({list: this.state.list.concat([newO...
import module from string variable
...=[''])
then i will refer to matplotlib.text.
In Python 2.7 and Python 3.1 or later, you can use importlib:
import importlib
i = importlib.import_module("matplotlib.text")
Some notes
If you're trying to import something from a sub-folder e.g. ./feature/email.py, the code will look like impor...
How do you delete an ActiveRecord object?
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It's destroy and destroy_all methods, like
user.destroy
User.find(15).destroy
User.destroy(15)
User.where(age: 20).destroy_all
User.destroy_all(age: 20)
Alternatively you can use delete and delete_all which won't enforce :before_destroy and :after_destroy callbacks or any dependent associ...
Ruby Hash to array of values
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answered Mar 5 '12 at 0:48
Ray ToalRay Toal
76.4k1212 gold badges143143 silver badges204204 bronze badges
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How to hide output of subprocess in Python 2.7
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edited Jun 30 '12 at 1:12
answered Jun 29 '12 at 22:15
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jQuery show for 5 seconds then hide
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answered Aug 7 '10 at 1:22
Nick Craver♦Nick Craver
580k125125 gold badges12551255 silver badges11351135 bronze badges
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Changing the color of the axis, ticks and labels for a plot in matplotlib
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167
As a quick example (using a slightly cleaner method than the potentially duplicate question):
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What do (lambda) function closures capture?
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163
Your second question has been answered, but as for your first:
what does the closure captu...