Real Python random percentage -


i don't understand syntax have found in real python book , hoping clarity.

from __future__ import division random import random  total_a_wins = 0 total_b_wins = 0  trials = 100000 trial in range(0, trials):     a_win = 0     b_win = 0     if random() < .87: # 1st region         a_win += 1     else:         b_win += 1     # determine overall election outcome     if a_win > b_win:         total_a_wins += 1     else:         total_b_wins += 1  print "probability wins:", total_a_wins/trials print "probability b wins:", total_b_wins/trials

so in exercise state has 87% chance of winning. how random () < .87 define 87%?

when read it states: if random less .87

this hoping clarify because random being less .87 doesn't make sense me.

the return value of random.random() uniformly distributed across range [0.0, 1.0) (so 0.0 inclusive 1.0 exclusive), has equal chance of hitting value in range.

that means 87% of time, values below .87 chosen.

if change test random() < 1.0, test pass always, 100% of time. if change random() < 0.0, it'd never pass, 0% of time. , since distribution uniform, random() < 0.5 true half of time, since other half of time values in range [0.5, 1.0) picked instead.

you @ dice roll; 100% of time, you'll roll value < 7 standard 6-sided dice. 0% of time you'll roll value < 1, 50% of time you'll roll value < 4 (1, 2 or 3), , 66.67% of time you'd roll value less 5 (so 2/3rds of rolls). random.random() return value has much larger range 6 distinct values.


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