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pandas: filter rows of DataFrame with operator chaining
... boolean index.
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, ...
deleting rows in numpy array
... [7,8,9]])
To delete the first row, do this:
x = numpy.delete(x, (0), axis=0)
To delete the third column, do this:
x = numpy.delete(x,(2), axis=1)
So you could find the indices of the rows which have a 0 in them, put them in a list or a tuple and pass this as the second argument of the...
Regular expression for matching latitude/longitude coordinates?
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answered Aug 19 '10 at 3:38
Eric CEric C
3,55633 gold badges2828 silver badges2626 bronze badges
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How do I convert a TimeSpan to a formatted string? [duplicate]
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edited Aug 16 '09 at 17:51
answered May 8 '09 at 22:22
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Sample random rows in dataframe
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460
First make some data:
> df = data.frame(matrix(rnorm(20), nrow=10))
> df
X1 ...
How to decide font color in white or black depending on background color?
...overall intensity of the color and choose the corresponding text.
if (red*0.299 + green*0.587 + blue*0.114) > 186 use #000000 else use #ffffff
The threshold of 186 is based on theory, but can be adjusted to taste. Based on the comments below a threshold of 150 may work better for you.
Edit: T...
Remove outline from select box in FF
...he color of the dotted border. So say if you do...
select {
color: rgba(0,0,0,0);
}
Firefox will render the dotted border transparent. But of course your text will be transparent too! So we must somehow display the text. text-shadow comes to the rescue:
select {
color: rgba(0,0,0,0);
text-...
How do I make an html link look like a button?
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answered Apr 2 '09 at 15:06
TStamperTStamper
28.2k1010 gold badges6161 silver badges7272 bronze badges
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Find XOR of all numbers in a given range
...ven a large range [a,b] where 'a' and 'b' can be typically between 1 and 4,000,000,000 inclusive. You have to find out the XOR of all the numbers in the given range.
...
How do you match only valid roman numerals with a regular expression?
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330
You can use the following regex for this:
^M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3...