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Fastest way to replace NAs in a large data.table
I have a large data.table , with many missing values scattered throughout its ~200k rows and 200 columns. I would like to re code those NA values to zeros as efficiently as possible.
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MySQL “incorrect string value” error when save unicode string in Django
...trange error message when tried to save first_name, last_name to Django's auth_user model.
9 Answers
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How to keep environment variables when using sudo
When I use any command with sudo the environment variables are not there. For example after setting HTTP_PROXY the command wget works fine without sudo . However if I type sudo wget it says it can't bypass the proxy setting.
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How do I modify fields inside the new PostgreSQL JSON datatype?
With postgresql 9.3 I can SELECT specific fields of a JSON data type, but how do you modify them using UPDATE? I can't find any examples of this in the postgresql documentation, or anywhere online. I have tried the obvious:
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MySQL DROP all tables, ignoring foreign keys
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I found the generated set of drop statements useful, and recommend these tweaks:
Limit the generated drops to your database like this:
SELECT concat('DROP TABLE IF EXISTS `', table_name, '`;')
FROM information_schema.tables...
Error 908: Permission Receive SMS - #5 by Taifun - MIT App Inventor Help - MIT App Inventor Community
:root {
--animation-state: paused;
}
/* user picked a theme where the "regular" scheme is dark */
/* user picked a theme a light scheme and also enabled a dark scheme */
/* deal with light scheme first */
@media (pref...
How to parse/format dates with LocalDateTime? (Java 8)
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Parsing date and time
To create a LocalDateTime object from a string you can use the static LocalDateTime.parse() method. It takes a string and a DateTimeFormatter as parameter. The DateTimeFormatter is used to specify the date/time pattern.
String str = "1986-04-08 12:30";
DateTimeFormatter fo...
Eclipse returns error message “Java was started but returned exit code = 1”
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Implicit “Submit” after hitting Done on the keyboard at the last EditText
I've used some apps where when I fill my username, then go to my password, if I hit "Done" on the keyboard, the login form is automatically submitted, without me having to click the submit button. How is this done?
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How to merge dictionaries of dictionaries?
I need to merge multiple dictionaries, here's what I have for instance:
29 Answers
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