Moving to Functional

[Gribouillis]

A quick fix is to not use numpy

from functools import reduce
import itertools as itt

ZERO = [0] * 10

def add_list(a, b):
    return [x + y for x, y in zip(a, b)]

    
def count_incr(rec):
    return [RecRan(rec, j) for j in range(10)]
 
def ireport_group(date, irec):
    return itt.chain(
        (StrRec(rec) for rec in irec),
        (Summary(
            len(irec),
            reduce(add_list, (count_incr(rec) for rec in irec), ZERO),
            Strdate(date)),))

def Report():
    return ''.join(
        itt.chain.from_iterable(
            ireport_group(date, list(irec))
                for date, irec in itt.groupby(Load(), key=RecToDate)))

Another solution is probably to install numpy 1.19.3 as suggested in the dev page that you linked.