spedscrambler.py

import collections
import datetime
import hashlib
import random
import string
import sys
from contextlib import suppress


random.seed(0)
done = collections.Counter()
maximum = 5


def max_for(text):
    hasher = hashlib.blake2b()
    hasher.update(text.encode('utf-8'))
    return sum(hasher.digest()) % maximum


def random_string(size=6, chars=string.ascii_uppercase + string.digits):
    return ''.join(random.choice(chars) for _ in range(size))


def scramble(value):
    # handle dates
    with suppress(Exception):
        datetime.datetime.strptime(value, "%d%m%Y")
        return value

    # handle floats
    with suppress(Exception):
        if ',' in value:
            float(value.replace(',', '.'))
            return value

    # identifiers, do not touch
    if value == "LECD" or value == "LECF":
        return value

    # randomize digits if only digits
    if value.isdigit():
        return random_string(size=len(value), chars=string.digits)

    # randomize generally
    return random_string(size=len(value))


def run(line):
    if not line.startswith('|'):
        return
    try:
        _, record_type, *values, _ = line.split('|')
    except Exception:
        return
    if done[record_type] < max_for(record_type):
        new_values = '|'.join(scramble(v) for v in values)
        print(f'|{record_type}|{new_values}|')
        done.update([record_type])


if __name__ == '__main__':
    filepath = sys.argv[1]
    with open(filepath, encoding='latin1') as f:
        for line in f:
            run(line)