如何最佳地存储50万个键值对？

Question

So, I have an object that has an ID attached to it. I need to do a lookup on that ID and get a different ID. I just don't know the most efficient way to do this.

Essentially, the transformation will look like this:

1 -> af567
2 -> at678
3 -> dh675

I will be doing this lookup in Python, and all these values are known before runtime. I thought about Json, SQLite, or a prebuilt dictionary, but I'm just not sure the most optimal route to take. There will be 500,000 of these pairs stored. I just need to know the optimal medium to store these pairs

Answer 1

Okay so you have 500.000 items where a number maps to a five-digit string:

Let's put that to the test

def five(i):
    """turns a number into an at least five-digit string"""
    s = hex(s).replace('0x', '')
    return '0' * (5 - len(s)) + s

# 500k items, no duplication
d = {}
for i in range(500000):
    d[i] = five(i)

# see https://code.activestate.com/recipes/577504/
total_size(d, verbose=False) / 1024 / 1024
# => 33.8720645904541 (megabytes)

That's nothing, really. Use a dict.