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How assignment works with Python list slice?
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116
You are confusing two distinct operation that use very similar syntax:
1) slicing:
b = a[0:2...
Converting a Pandas GroupBy output from Series to DataFrame
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g1 here is a DataFrame. It has a hierarchical index, though:
In [19]: type(g1)
Out[19]: pandas.core.frame.DataFrame
In [20]: g1.index
Out[20]:
MultiIndex([('Alice', 'Seattle'), ('Bob', 'Seattle'), ('Mallory', 'Portland'),
...
Why is a round-trip conversion via a string not safe for a double?
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178
I found the bug.
.NET does the following in clr\src\vm\comnumber.cpp:
DoubleToNumber(value, ...
What does the “map” method do in Ruby?
...e from the block (the original object is unchanged unless you use map!):
[1, 2, 3].map { |n| n * n } #=> [1, 4, 9]
Array and Range are enumerable types. map with a block returns an Array. map! mutates the original array.
Where is this helpful, and what is the difference between map! and each...
Standard deviation of a list
I want to find mean and standard deviation of 1st, 2nd,... digits of several (Z) lists. For example, I have
8 Answers
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How to add leading zeros?
...of digits to begin with, so let's try a harder example of making powers of 10 width 8 too.
anim <- 25499:25504
x <- 10 ^ (0:5)
paste (and it's variant paste0) are often the first string manipulation functions that you come across. They aren't really designed for manipulating numbers, but...
How to check Django version
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691
Django 1.5 supports Python 2.6.5 and later.
If you're under Linux and want to check the Python ...
How do I profile memory usage in Python?
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123
This one has been answered already here: Python memory profiler
Basically you do something li...
How random is JavaScript's Math.random?
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183
Given numbers between 1 and 100.
9 have 1 digit (1-9)
90 have 2 digits (10-99)
1 has 3 digi...
Jasmine.js comparing arrays
...n() {
it('passes if arrays are equal', function() {
var arr = [1, 2, 3];
expect(arr).toEqual([1, 2, 3]);
});
});
Just for information:
toBe() versus toEqual(): toEqual() checks equivalence. toBe(), on the
other hand, makes sure that they're the exact same object.
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