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How to generate all permutations of a list?
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Starting with Python 2.6 (and if you're on Python 3) you have a standard-library tool for this: itertools.permutations.
import itertools
list(itertools.permutations([1, 2, 3]))
If you're using an older Python (<2.6) for some re...
How to version control a record in a database
... a FOO table that admins and users can update. Most of the time you can write queries against the FOO table. Happy days.
Then, I would create a FOO_HISTORY table. This has all the columns of the FOO table. The primary key is the same as FOO plus a RevisionNumber column. There is a foreign key ...
Efficiently test if a port is open on Linux?
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To determine if someone is listening, attempt to connect by loopback. If it fails, then the port is closed or we aren't allowed access. Afterwards, close the connection.
Modify this for your use case, such as sending an email, exiting the script on failure, or starting the required service.
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jQuery hasAttr checking to see if there is an attribute on an element [duplicate]
...there is an attribute on an element in jQuery? Similar to hasClass , but with attr ?
9 Answers
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jQuery's .click - pass parameters to user function
I am trying to call a function with parameters using jQuery's .click, but I can't get it to work.
7 Answers
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Programmatically selecting text in an input field on iOS devices (mobile Safari)
...follow
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edited Mar 20 '19 at 6:46
Stalinko
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Python regular expressions return true/false
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It may be more desirable to use if re.match(...) is None: instead
– NuclearPeon
Feb 1 '17 at 22:42
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Difference between map and collect in Ruby?
... and multi-paradigm languages as well: In C++'s Standard Template Library, it is called transform, in C# (3.0)'s LINQ library, it is provided as an extension method called Select. Map is also a frequently used operation in high level languages such as Perl, Python and Ruby; the operation is called m...
Add line break to 'git commit -m' from the command line
I am using Git from the command line and am trying to add a line break to the commit message (using git commit -m "" ) without going into Vim.
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Smart pointers: who owns the object? [closed]
... deallocation when the counter reaches zero
weak_ptr - same as above, but it's a 'slave' for a shared_ptr, can't deallocate
auto_ptr - when the creation and deallocation happen inside the same function, or when the object has to be considered one-owner-only ever. When you assign one pointer to ano...