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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 ...
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...
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...
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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Difference between a Structure and a Union
Is there any good example to give the difference between a struct and a union ?
Basically I know that struct uses all the memory of its member and union uses the largest members memory space. Is there any other OS level difference?
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Is there an expression for an infinite generator?
Is there a straight-forward generator expression that can yield infinite elements?
7 Answers
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