import json
a = [
    dict(username="dev_1009048", password="e60be16cbfeebdb4d4c7dd7c0a6f2f67", nickname="", avatar=""),
    dict(username="dev_1009049", password="e60be16cbfeebdb4d4c7dd7c0a6f2f67", nickname="", avatar=""),
    dict(username="dev_1009050", password="e60be16cbfeebdb4d4c7dd7c0a6f2f67", nickname="", avatar="")
]
b = json.dumps(a)
print(b)