json_to_csv.python

#!/usr/bin/env python3
import sys, json, csv, string

if len(sys.argv) != 3:
    sys.exit("usage: json2csv.py input.json output.csv")

try:
    data = json.load(open(sys.argv[1]))
except Exception:
    sys.exit("invalid json")

if set(data) != {"CORE", "LB", "PAR"}:
    sys.exit("invalid categories")

arches = []
seen = set()
for cat in data.values():
    if not isinstance(cat, dict):
        sys.exit("data not 2-dimensional")
    for param in cat.values():
        if not isinstance(param, dict):
            sys.exit("data not 2-dimensional")
        for a in param.keys():
            if a not in seen:
                seen.add(a)
                arches.append(a)

cols = 1 + len(arches)
empty = [""] * cols
arches = sorted(arches, key=lambda x: 0 if x.startswith("default") else 1)

with open(sys.argv[2], "w", newline="") as f:
    w = csv.writer(f, lineterminator="\n")
    w.writerow(["Architecture", *arches])
    w.writerow(empty)
    cats = list(data.items())
    for ci, (cname, cat) in enumerate(cats):
        w.writerow([f"{cname}:"] + [""] * (cols - 1))
        for pname, param in cat.items():
            row = [pname]
            for a in arches:
                v = param.get(a, "")
                if isinstance(v, list):
                  row.append(json.dumps(v))
                elif isinstance(v, str) and not v == "":
                   row.append('"' + v + '"')
                else:
                   row.append(v)
            w.writerow(row)
        if ci != len(cats) - 1:
            w.writerow(empty)