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R - Concatenate two dataframes?
... line adds column b to data frame b.
Results
> a <- data.frame(a=c(0,1,2), b=c(3,4,5), c=c(6,7,8))
> a
a b c
1 0 3 6
2 1 4 7
3 2 5 8
> b <- data.frame(a=c(9,10,11), c=c(12,13,14))
> b
a c
1 9 12
2 10 13
3 11 14
> b$b <- NA
> b
a c b
1 9 12 NA
2 10 13 NA
3 11...
Deleting lines from one file which are in another file
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answered Jan 24 '11 at 9:06
gabuzogabuzo
6,27833 gold badges2323 silver badges3535 bronze badges
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Regular expression to allow spaces between words
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tl;dr
Just add a space in your character class.
^[a-zA-Z0-9_ ]*$
Now, if you want to be strict...
The above isn't exactly correct. Due to the fact that * means zero or more, it would match all of the following cases that one would not usually mean to match:
An empty str...
Colspan all columns
...en the HTML is being rendered)? w3schools mentions you can use colspan="0" , but it doesn't say exactly what browsers support that value (IE 6 is in our list to support).
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Use jQuery to get the file input's selected filename without the path
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edited Jun 16 '11 at 0:37
answered Jun 16 '11 at 0:21
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Capture characters from standard input without waiting for enter to be pressed
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101
That's not possible in a portable manner in pure C++, because it depends too much on the termin...
Better way to shuffle two numpy arrays in unison
...ple: Let's assume the arrays a and b look like this:
a = numpy.array([[[ 0., 1., 2.],
[ 3., 4., 5.]],
[[ 6., 7., 8.],
[ 9., 10., 11.]],
[[ 12., 13., 14.],
[ 15., 16., 17.]]])
b = numpy.a...
How to convert a string to integer in C?
...ns in C99. For example you could say:
uintmax_t num = strtoumax(s, NULL, 10);
if (num == UINTMAX_MAX && errno == ERANGE)
/* Could not convert. */
Anyway, stay away from atoi:
The call atoi(str) shall be equivalent to:
(int) strtol(str, (char **)NULL, 10)
except that the han...
The order of keys in dictionaries
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80
You could use OrderedDict (requires Python 2.7) or higher.
Also, note that OrderedDict({'a': 1,...
How to calculate a mod b in Python?
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answered Jun 13 '09 at 16:59
eduffyeduffy
34.1k99 gold badges9090 silver badges8989 bronze badges
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