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How assignment works with Python list slice?
...g two distinct operation that use very similar syntax:
1) slicing:
b = a[0:2]
This makes a copy of the slice of a and assigns it to b.
2) slice assignment:
a[0:2] = b
This replaces the slice of a with the contents of b.
Although the syntax is similar (I imagine by design!), these are two di...
Twitter's typeahead.js suggestions are not styled (have no border, transparent background, etc.)
I'm using twitter's typeahead.js 0.9.3 and it seems my suggestions are not styled at all.
9 Answers
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How to determine if a list of polygon points are in clockwise order?
...se. (The result is twice the enclosed area, with a +/- convention.)
point[0] = (5,0) edge[0]: (6-5)(4+0) = 4
point[1] = (6,4) edge[1]: (4-6)(5+4) = -18
point[2] = (4,5) edge[2]: (1-4)(5+5) = -30
point[3] = (1,5) edge[3]: (1-1)(0+5) = 0
point[4] = (1,0) edge[4]: (5-1)(0+0) = 0
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
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Since dplyr 0.8 group_by gained the .drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a)...
Wolfram's Rule 34 in XKCD [closed]
The hover "joke" in #505 xkcd touts "I call rule 34 on Wolfram's Rule 34".
12 Answers
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Why are elementwise additions much faster in separate loops than in a combined loop?
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10 Answers
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Most efficient way to create a zero filled JavaScript array?
...duces Array.prototype.fill. It can be used like this:
new Array(len).fill(0);
Not sure if it's fast, but I like it because it's short and self-describing.
It's still not in IE (check compatibility), but there's a polyfill available.
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Why isn't my Pandas 'apply' function referencing multiple columns working? [closed]
...[44]: df
Out[44]:
a b c Value
0 -1.674308 foo 0.343801 0.044698
1 -2.163236 bar -2.046438 -0.116798
2 -0.199115 foo -0.458050 -0.199115
3 0.918646 bar -0.007185 -0.001006
4 1.336830 foo 0.534292 0.268245
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Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
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As Sven mentioned, x[[[0],[2]],[1,3]] will give back the 0 and 2 rows that match with the 1 and 3 columns while x[[0,2],[1,3]] will return the values x[0,1] and x[2,3] in an array.
There is a helpful function for doing the first example I gave, n...
How do I check if there are duplicates in a flat list?
...
406
Use set() to remove duplicates if all values are hashable:
>>> your_list = ['one', 't...