fractional-indexing

0.1.3 verified Mon Apr 27 auth: no python

A Python implementation of fractional indexing for generating ordering strings (keys) between others, commonly used for sortable IDs in collaborative applications. Current version 0.1.3, stable maintenance mode.

pip install fractional-indexing

Common errors

error ImportError: cannot import name 'generate_key_between' from 'fractional_indexing' ↓

cause The function was renamed in older versions. In 0.1.2+, it's available as 'generate_key'.

fix

Use 'from fractional_indexing import generate_key' (and call it with between= and after= parameters).

error TypeError: generate_key() missing 3 required positional arguments: 'start', 'end', and 'before_or_after' ↓

cause Using an incorrect function signature; the function expects keyword arguments, not positional.

fix

Use keyword arguments: generate_key(between='a0', after='a2') or generate_key() for the first key.

error ValueError: after must be greater than before ↓

cause The 'after' key must be lexicographically greater than the 'between' key (or the before/between key).

fix

Ensure the 'after' argument is lexicographically larger than the 'between' argument.

Warnings

gotcha The library is not widely tested for concurrent generation; concurrent calls may produce duplicate keys if shared state is not managed. ↓

fix Ensure single-threaded or use a locking mechanism if generating keys in a multithreaded context.

gotcha Keys are not guaranteed to be unique across multiple independent generators with the same initial state. Always start with no arguments to get a unique initial key per session. ↓

fix Do not reuse keys across different datasets without proper context separation; generate a fresh initial key for each independent ordering.

gotcha The library does not support specifiying a custom base-digit set. It uses a fixed 62-digit set internally. ↓

fix If you need custom encoding, consider forking the library or using another approach.

Imports

generate_key
```
from fractional_indexing import generate_key
```
Main function to generate a key between two others.
generate_key_between
```
from fractional_indexing import generate_key_between
```
Alternative name for the same function (alias).

BASE_62_DIGITS

from fractional_indexing import BASE_62_DIGITS

Base62 digit set used internally.

Quickstart

Basic usage of generate_key to create ordering strings.

from fractional_indexing import generate_key

# Generate first key
key1 = generate_key()
print(key1)  # e.g., 'a0'

# Generate key after key1
key2 = generate_key(after=key1)
print(key2)  # e.g., 'a1'

# Generate key between key1 and key2
key_between = generate_key(between=key1, after=key2)
print(key_between)  # e.g., 'a0V'