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Weighted random numbers
...andom number that is 0 or greater and is less than the sum of the weights
3) go through the items one at a time, subtracting their weight from your random number, until you get the item where the random number is less than that item's weight
Pseudo-code illustrating this:
int sum_of_weight = 0;
f...
Split list into smaller lists (split in half)
...
238
A = [1,2,3,4,5,6]
B = A[:len(A)//2]
C = A[len(A)//2:]
If you want a function:
def split_list...
How to print a percentage value in python?
...age floating point precision type:
>>> print "{0:.0%}".format(1./3)
33%
If you don't want integer division, you can import Python3's division from __future__:
>>> from __future__ import division
>>> 1 / 3
0.3333333333333333
# The above 33% example would could now be w...
Most efficient way of making an if-elif-elif-else statement when the else is done the most?
...:
the_thing = 2
elif something == 'there':
the_thing = 3
else:
the_thing = 4
2.py
something = 'something'
options = {'this': 1, 'that': 2, 'there': 3}
for i in xrange(1000000):
the_thing = options.get(something, 4)
3.py
something = 'something'
options = {'t...
How to create a density plot in matplotlib?
...mpy as np
from scipy.stats import gaussian_kde
data = [1.5]*7 + [2.5]*2 + [3.5]*8 + [4.5]*3 + [5.5]*1 + [6.5]*8
density = gaussian_kde(data)
xs = np.linspace(0,8,200)
density.covariance_factor = lambda : .25
density._compute_covariance()
plt.plot(xs,density(xs))
plt.show()
I get
which is pretty...
Algorithms based on number base systems? [closed]
...
39
Chris Okasaki has a very good chapter in his book Purely Functional Data Structures that discus...
What are the aspect ratios for all Android phone and tablet devices?
...═════════════════╣
║ 5 x 3 ║ 0.6 ║ 1.667... ║
╠══════════════════════════╬════════════════════════...
Python “extend” for a dictionary
...
phoenix
3,20611 gold badge2727 silver badges3131 bronze badges
answered Feb 23 '09 at 11:01
Nick FortescueNic...
App Inventor 2 数学代码块 · App Inventor 2 中文网
... ( ^ )
返回第一个数字的第二个数字次幂的结果。比如2^3 = 222 = 8
随机整数 (random integer)
返回给定值之间（包含首尾）的随机整数值。参数的顺序不限，也就是 1~100 和 100~1 效果一样。
随机小数 (random fraction)
返回 0 到 1 ...