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Change a column type from Date to DateTime during ROR migration
I need to change my column type from date to datetime for an app I am making. I don't care about the data as its still being developed.
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What is the best way to get all the divisors of a number?
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To expand on what Shimi has said, you should only be running your loop from 1 to the square root of n. Then to find the pair, do n / i, and this will cover the whole problem space.
As was also noted, this is a NP, or 'difficult' problem. Exhaustive search, the way you are doing it, is about as ...
Remove all special characters, punctuation and spaces from string
I need to remove all special characters, punctuation and spaces from a string so that I only have letters and numbers.
16 A...
Small Haskell program compiled with GHC into huge binary
...ibm.so.6 => /lib/libm.so.6 (0x00007fb21e706000)
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You see from the ldd output that GHC has produced a dynamically linked executable, but only the C libraries are dynamically linked! All the Haskell libraries are copied in verbatim.
Aside: since this is a graphics-intensive app, I'd...
Auto Scale TextView Text to Fit within Bounds
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From June 2018 Android officially started supporting this feature for Android 4.0 (API level 14) and higher.
Check it out at: Autosizing TextViews
With Android 8.0 (API level 26) and higher:
<?xml version="1.0" encoding...
Assert a function/method was not called using Mock
... @NathanArthur Hm, I don't think so, after sudo easy_install -U mock and from mock import Mock on MacOS, the above runs without a hitch. Never installed Django :)
– Joachim Isaksson
Nov 19 '14 at 16:11
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How to write LaTeX in IPython Notebook?
... Now is working on Jupiter. I put %%latex in a cell, and import the from IPython.display import Latex. After that, the Jupyter notebook recognizes Latex notation.
– Miguel Gutierrez
Jun 28 at 3:42
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Are Javascript arrays sparse?
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How exactly JavaScript arrays are implemented differs from browser to browser, but they generally fall back to a sparse implementation - most likely the same one used for property access of regular objects - if using an actual array would be inefficient.
You'll have to ask some...
Run function from the command line
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Alternatively, if you don't care about namespace pollution:
$ python -c 'from foo import *; print hello()'
And the middle ground:
$ python -c 'from foo import hello; print hello()'
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In mongoDb, how do you remove an array element by its index?
...ions. If we need the operation to be atomic, we could:
Read the document from the database
Update the document and remove the item in the array
Replace the document in the database. To ensure the document has not changed since we read it, we can use the update if current pattern described in the m...