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How to reset a single table in rails?
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A lot of people (like me) come here to find how to delete all the data in the table. Here you go:
$ rails console
> ModelName.delete_all
or
> ModelName.destroy_all
destroy_all checks dependencies and callbacks, and takes a little longer.
delete_all is a straight SQL que...
How does a Breadth-First Search work when looking for Shortest Path?
I've done some research, and I seem to be missing one small part of this algorithm. I understand how a Breadth-First Search works, but I don't understand how exactly it will get me to a specific path, as opposed to just telling me where each individual node can go. I guess the easiest way to explain...
How can I find all matches to a regular expression in Python?
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Use re.findall or re.finditer instead.
re.findall(pattern, string) returns a list of matching strings.
re.finditer(pattern, string) returns an iterator over MatchObject objects.
Example:
re.findall( r'all (.*?) are', 'all cats are s...
Replace String in all files in Eclipse
Do you know how can I search an replace a String in all files of my current project?
10 Answers
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Generate all permutations of a list without adjacent equal elements
...is greedy algorithm returns optimal solutions, by the following logic. We call a prefix (partial solution) safe if it extends to an optimal solution. Clearly the empty prefix is safe, and if a safe prefix is a whole solution then that solution is optimal. It suffices to show inductively that each gr...
Algorithm to generate all possible permutations of a list?
...n! possible ways to order these elements. What is an algorithm to generate all possible orderings of this list? Example, I have list [a, b, c]. The algorithm would return [[a, b, c], [a, c, b,], [b, a, c], [b, c, a], [c, a, b], [c, b, a]].
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Safely limiting Ansible playbooks to a single machine?
I'm using Ansible for some simple user management tasks with a small group of computers. Currently, I have my playbooks set to hosts: all and my hosts file is just a single group with all machines listed:
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How do I get PHP errors to display?
...ile ( php.ini ) and display_errors is set and also error reporting is E_ALL . I have restarted my Apache webserver.
26 A...
All falsey values in JavaScript
...RemoteJob)
"", '' and `` - strings of length 0
null
undefined
NaN
document.all (in HTML browsers only)
This is a weird one. document.all is a falsey object, with typeof as undefined. It was a Microsoft-proprietory function in IE before IE11, and was added to the HTML spec as a "willful violation ...
Using Emacs to recursively find and replace in text files not already open
...to find out how to do something like this which should be easy, that especially stops me from getting more used to using Emacs and instead starting up the editor I'm already familiar with. I use the example here fairly often in editing multiple files.
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