with open(sys.argv[1], 'r') if len(sys.argv) > 1 else sys.stdin as fp:
data = json.load(fp)
for t in data.get("transactions"):
with open(sys.argv[1], 'r') if len(sys.argv) > 1 else sys.stdin as fp:
data = json.load(fp)
for t in data.get("transactions"):