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Adding :default => true to boolean in existing Rails column
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change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...an work around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's...
How to go about formatting 1200 to 1.2k in java
...ng, String> suffixes = new TreeMap<> ();
static {
suffixes.put(1_000L, "k");
suffixes.put(1_000_000L, "M");
suffixes.put(1_000_000_000L, "G");
suffixes.put(1_000_000_000_000L, "T");
suffixes.put(1_000_000_000_000_000L, "P");
suffixes.put(1_000_000_000_000_000_000L, "E");
}
publ...
Does IMDB provide an API? [closed]
...lo.json (alternate)
Format: JSON-P
Caveat: It's in JSON-P format, and the callback parameter can not customised. To use it cross-domain you'll have to use the function name they choose (which is in the imdb${searchphrase} format). Alternatively, one could strip or replace the padding via a local pro...
How to deep copy a list?
... don't make a deep copy using list() (Both list(...) and testList[:] are shallow copies).
You use copy.deepcopy(...) for deep copying a list.
deepcopy(x, memo=None, _nil=[])
Deep copy operation on arbitrary Python objects.
See the following snippet -
>>> a = [[1, 2, 3], [4, 5, 6]]...
How to sort a list in Scala by two fields?
... @SachinK: You could implement customOrdering as Ordering[Row] manually or using Ordering.by like this: val customOrdering = Ordering.by((r: Row) => (r.lastName, r.firstName))( Ordering.Tuple2(Ordering.String.reverse, Ordering.String) )`
– senia
Jun ...
pythonic way to do something N times without an index variable?
...ghtly faster approach than looping on xrange(N) is:
import itertools
for _ in itertools.repeat(None, N):
do_something()
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ruby send method passing multiple parameters
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send("i_take_multiple_arguments", *[25.0,26.0]) #Where star is the "splat" operator
or
send(:i_take_multiple_arguments, 25.0, 26.0)
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How do I get current date/time on the Windows command line in a suitable format for usage in a file/
Update: Now that it's 2016 I'd use PowerShell for this unless there's a really compelling backwards-compatible reason for it, particularly because of the regional settings issue with using date . See @npocmaka's https://stackoverflow.com/a/19799236/8479
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What do the python file extensions, .pyc .pyd .pyo stand for?
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.py: This is normally the input source code that you've written.
.pyc: This is the compiled bytecode. If you import a module, python will build a *.pyc file that contains the bytecode to make importing it again later easier (and faster).
.pyo...