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Python creating a dictionary of lists
...s import defaultdict
>>> d = defaultdict(list)
>>> a = ['1', '2']
>>> for i in a:
... for j in range(int(i), int(i) + 2):
... d[j].append(i)
...
>>> d
defaultdict(<type 'list'>, {1: ['1'], 2: ['1', '2'], 3: ['2']})
>>> d.items()
[(1, ['1']), (...
What is the difference between Ruby 1.8 and Ruby 1.9
I'm not clear on the differences between the "current" version of Ruby (1.8) and the "new" version (1.9). Is there an "easy" or a "simple" explanation of the differences and why it is so different?
...
Convert numpy array to tuple
...
161
>>> arr = numpy.array(((2,2),(2,-2)))
>>> tuple(map(tuple, arr))
((2, 2), (2...
Append column to pandas dataframe
...
135
It seems in general you're just looking for a join:
> dat1 = pd.DataFrame({'dat1': [9,5]})...
jQuery map vs. each
...ion you can potentially waste a lot of memory.
For example:
var items = [1,2,3,4];
$.each(items, function() {
alert('this is ' + this);
});
var newItems = $.map(items, function(i) {
return i + 1;
});
// newItems is [2,3,4,5]
You can also use the map function to remove an item from an array...
How does numpy.histogram() work?
...
169
A bin is range that represents the width of a single bar of the histogram along the X-axis. Yo...
What's the difference between RANK() and DENSE_RANK() functions in oracle?
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10 Answers
10
Active
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Is it possible to install another version of Python to Virtualenv?
...
12 Answers
12
Active
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Efficient way to apply multiple filters to pandas DataFrame or Series
...numpy) allow for boolean indexing, which will be much more efficient:
In [11]: df.loc[df['col1'] >= 1, 'col1']
Out[11]:
1 1
2 2
Name: col1
In [12]: df[df['col1'] >= 1]
Out[12]:
col1 col2
1 1 11
2 2 12
In [13]: df[(df['col1'] >= 1) & (df['col1'] <=1 )]
Out...
What's the difference between “mod” and “remainder”?
...
145
There is a difference between modulus and remainder. For example:
-21 mod 4 is 3 because -21 ...