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Why does csvwriter.writerow() put a comma after each character?
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151
It expects a sequence (eg: a list or tuple) of strings. You're giving it a single string. A str...
Run a callback only if an attribute has changed in Rails
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Rails 5.1+
class Page < ActiveRecord::Base
before_save :do_something, if: :will_save_change_to_status_id?
private
def do_something
# ...
end
end
The commit that changed ActiveRecord::Dirty is here: https://githu...
Xcode 4 - “Archive” is greyed out?
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Rafael Bugajewski
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answered Mar 11 '11 at 0:05
jasonjason
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Responding with a JSON object in Node.js (converting object/array to JSON string)
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edited Dec 4 '17 at 6:25
answered Mar 21 '12 at 14:03
Ke...
How do you install ssh-copy-id on a Mac?
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5 Answers
5
Active
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relative path in require_once doesn't work
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edited Jan 14 '14 at 17:54
DarkSide
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answered Ma...
finding and replacing elements in a list
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>>> a= [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1]
>>> for n, i in enumerate(a):
... if i == 1:
... a[n] = 10
...
>>> a
[10, 2, 3, 4, 5, 10, 2, 3, 4, 5, 10]
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Change how fast “title” attribute's tooltip appears
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5 Answers
5
Active
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Why does PostgreSQL perform sequential scan on indexed column?
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If the SELECT returns more than approximately 5-10% of all rows in the table, a sequential scan is much faster than an index scan.
This is because an index scan requires several IO operations for each row (look up the row in the index, then retrieve the row from the h...
How do you get the width and height of a multi-dimensional array?
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answered Nov 23 '10 at 19:52
Reed CopseyReed Copsey
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