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Writing a Python list of lists to a csv file
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312
Python's built-in CSV module can handle this easily:
import csv
with open("output.csv", "wb"...
Useful code which uses reduce()? [closed]
...me a lot...
Here's some cute usages:
Flatten a list
Goal: turn [[1, 2, 3], [4, 5], [6, 7, 8]] into [1, 2, 3, 4, 5, 6, 7, 8].
reduce(list.__add__, [[1, 2, 3], [4, 5], [6, 7, 8]], [])
List of digits to a number
Goal: turn [1, 2, 3, 4, 5, 6, 7, 8] into 12345678.
Ugly, slow way:
int("".join(ma...
Javascript calculate the day of the year (1 - 366)
How do I use javascript to calculate the day of the year, from 1 - 366? For example:
22 Answers
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Rails 3: Get Random Record
...NDOM()") # For MySQL :order => "RAND()", - thanx, @DanSingerman
# Rails 3
Thing.order("RANDOM()").first
or
Thing.first(:offset => rand(Thing.count))
# Rails 3
Thing.offset(rand(Thing.count)).first
Actually, in Rails 3 all examples will work. But using order RANDOM is quite slow for big ta...
How to have the cp command create any necessary folders for copying a file to a destination [duplica
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283
To expand upon Christian's answer, the only reliable way to do this would be to combine mkdir an...
Disable ALL CAPS menu items in Visual Studio 2013
In Visual Studio 2013, Microsoft again presents the menu in UPPERCASE as the default.
6 Answers
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Flatten nested dictionaries, compressing keys
...;> flatten({'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y' : 10}}, 'd': [1, 2, 3]})
{'a': 1, 'c_a': 2, 'c_b_x': 5, 'd': [1, 2, 3], 'c_b_y': 10}
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How does the Brainfuck Hello World actually work?
...ctual cell.
Take a look at ASCII table. For example, decimal code of ! is 33, while a is 97.
Well, lets imagine your BF program memory looks like:
...[0][0][*0*][0][0]...
Assuming standard input stands for a, if you use comma , operator, what BF does is read a decimal ASCII code 97 to memory:
...
What would cause an algorithm to have O(log n) complexity?
...o have that log2 16 = 4. Hmmm... what about 128?
128 / 2 = 64
64 / 2 = 32
32 / 2 = 16
16 / 2 = 8
8 / 2 = 4
4 / 2 = 2
2 / 2 = 1
This took seven steps, and log2 128 = 7. Is this a coincidence? Nope! There's a good reason for this. Suppose that we divide a number n by 2 i times. Then...
How to dump a table to console?
...e from Penlight:
> t = { a = { b = { c = "Hello world!", 1 }, 2, d = { 3 } } }
> require 'pl.pretty'.dump(t)
{
a = {
d = {
3
},
b = {
c = "Hello world!",
1
},
2
}
}
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