Let's say i have a dict
{'option one': 5.0, 'option two': 5.0, 'option three': 10.0}
How can i randomly select a key based on the probabilities above (ie. option one and two will have a 25% of being chosen. Option 3 would have a 50% chance of being chosen)
As a one liner:
import random
random.seed(100)
d = {'option one': 5.0, 'option two': 5.0, 'option three': 10.0}
picked = random.choices(*zip(*d.items()))[0]
print(picked)
# option one
More broken down:
import random
random.seed(100)
d = {'option one': 5.0, 'option two': 5.0, 'option three': 10.0}
# Key-value pairs in dictionary
items = d.items()
# "Transpose" items: from key-value pairs to sequence of keys and sequence of values
values, weights = zip(*items)
# Weighted choice (of one element)
picked = random.choices(values, weights)[0]
print(picked)
# option one
Note random.choices (which, unlike random.choice, offers a weights parameter) was added on Python 3.6.
