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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...
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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Xcode 4 - “Archive” is greyed out?
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Rafael Bugajewski
1,55833 gold badges2020 silver badges3636 bronze badges
answered Mar 11 '11 at 0:05
jasonjason
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How do you install ssh-copy-id on a Mac?
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5 Answers
5
Active
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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...
relative path in require_once doesn't work
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edited Jan 14 '14 at 17:54
DarkSide
3,34711 gold badge2222 silver badges3131 bronze badges
answered Ma...
Change how fast “title” attribute's tooltip appears
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5 Answers
5
Active
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Git: How to remove file from historical commit?
I have commit with id 56f06019 (for example). In that commit i have accidentally commited large file (50Mb). In another commit i add the same file but in the right size (small). Now my repo when i clone is too heavy :( How to remove that large file from repo history to reduce the size of my repo ?
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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...