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Repeat each row of data.frame the number of times specified in a column
...), 1:2]
Result:
var1 var2
1 a d
2 b e
2.1 b e
3 c f
3.1 c f
3.2 c f
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How do you detect Credit card type based on number?
...a card numbers start with a 4.
MasterCard: ^5[1-5][0-9]{5,}|222[1-9][0-9]{3,}|22[3-9][0-9]{4,}|2[3-6][0-9]{5,}|27[01][0-9]{4,}|2720[0-9]{3,}$ Before 2016, MasterCard numbers start with the numbers 51 through 55, but this will only detect MasterCard credit cards; there are other cards issued using t...
range over interface{} which stores a slice
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Is there a way to detect if an image is blurry?
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135
Yes, it is. Compute the Fast Fourier Transform and analyse the result. The Fourier transform te...
How to check if type of a variable is string?
...d to test whether an object is an instance of str or unicode.
In Python 3.x, the correct test is
isinstance(s, str)
The bytes class isn't considered a string type in Python 3.
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List comprehension rebinds names even after scope of comprehension. Is this right?
...omprehensions leak the loop control variable in Python 2 but not in Python 3. Here's Guido van Rossum (creator of Python) explaining the history behind this:
We also made another change in Python
3, to improve equivalence between list
comprehensions and generator
expressions. In Python 2,...
How to overcome TypeError: unhashable type: 'list'
...else:
d[key] = [value]
print d
# {'AAA': ['111', '112'], 'AAC': ['123'], 'AAB': ['111']}
Note that if you are using Python 3.x, you'll have to make a minor adjustment to get it work properly. If you open the file with rb, you'll need to use line = line.split(b'x') (which makes sure you are ...
In an array of objects, fastest way to find the index of an object whose attributes match a search
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394
Maybe you would like to use higher-order functions such as "map".
Assuming you want search by ...
Precision String Format Specifier In Swift
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30 Answers
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How do I detect the Python version at runtime? [duplicate]
I have a Python file which might have to support Python versions < 3.x and >= 3.x. Is there a way to introspect the Python runtime to know the version which it is running (for example, 2.6 or 3.2.x )?
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