key = "2000000004"
with open("file.json","r") as inp, open("temp.json", "w") as out:
for line in inp:
linej=json.loads(line)
if key in linej:
linej[key]["amv"] = False
line = json.dumps(linej)+"\n"
out.write(line)
os.remove("file.json")
os.rename("temp.json","file.json")