Probability of collision with ULIDs on a 50 million years period

collision_probability.py

"""
ULID probability of collision
"""

import decimal

# A ULID uses 80 bits of entropy
d = decimal.Decimal(2**80)

# Generate 1,000 ULIDs per millisecond (1,000,000 per second)
n = decimal.Decimal(1000)

# Probability that all ULIDs are different in 1 millisecond (https://en.wikipedia.org/wiki/Birthday_problem)
p = (-n**2 / (2*d)).exp()

# Probability of collision in 50 million years
millisecond = 1
second = 1000 * millisecond
hour = 3600 * second
day = 24 * hour
year = 365 * day
pc = 1 - p**(50*1000*1000*year)

# Results
print "p =", p
print "pc =", pc

I can't fathom how good python is for tasks like these