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How to use/install gcc on Mac OS X 10.8 / Xcode 4.4
I have install Mountain Lion (Mac OS X 10.8) and now gcc doesn't seem to be available anymore. I've also installed Xcode 4.4 so there is no more /Developer directory.
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How to sort a list of strings?
...f the list, without changing the original, use the sorted() function:
for x in sorted(mylist):
print x
However, the examples above are a bit naive, because they don't take locale into account, and perform a case-sensitive sorting. You can take advantage of the optional parameter key to specif...
Getting the class name of an instance?
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Have you tried the __name__ attribute of the class? ie type(x).__name__ will give you the name of the class, which I think is what you want.
>>> import itertools
>>> x = itertools.count(0)
>>> type(x).__name__
'count'
If you're still using Python 2, note ...
What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?
...ly)
DB2
Turns out they all use the same specification (with a few minor exceptions noted below) but support various combinations of those types (Oracle not included because it has just a NUMBER datatype, see the above link):
| SQL Server MySQL Postgres DB2
-------------------...
How to read data when some numbers contain commas as thousand separator?
I have a csv file where some of the numerical values are expressed as strings with commas as thousand separator, e.g. "1,513" instead of 1513 . What is the simplest way to read the data into R?
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Replace all 0 values to NA
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Replacing all zeroes to NA:
df[df == 0] <- NA
Explanation
1. It is not NULL what you should want to replace zeroes with. As it says in ?'NULL',
NULL represents the null object in R
which is unique and, I guess, can be seen as the most uninformative and empty object...
How to call shell commands from Ruby
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This explanation is based on a commented Ruby script from a friend of mine. If you want to improve the script, feel free to update it at the link.
First, note that when Ruby calls out to a shell, it typically calls /bin/sh, not Ba...
Reference alias (calculated in SELECT) in WHERE clause
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You can't reference an alias except in ORDER BY because SELECT is the second last clause that's evaluated. Two workarounds:
SELECT BalanceDue FROM (
SELECT (InvoiceTotal - PaymentTotal - CreditTotal) AS BalanceDue
FROM Invoices
) AS x
WHERE BalanceDu...
Add up a column of numbers at the Unix shell
Given a list of files in files.txt , I can get a list of their sizes like this:
20 Answers
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How can I use goto in Javascript?
I have some code that I absolutely must implement using goto . For example, I want to write a program like this:
16 Answer...