df = [
{"city": "Seattle", "month": "Apr", "precip": 2.68},
{"city": "Seattle", "month": "Aug", "precip": 0.87},
{"city": "Seattle", "month": "Dec", "precip": 5.31},
{"city": "New York", "month": "Apr", "precip": 3.94},
{"city": "New York", "month": "Aug", "precip": 4.13},
{"city": "New York", "month": "Dec", "precip": 3.58},
{"city": "Chicago", "month": "Apr", "precip": 3.62},
{"city": "Chicago", "month": "Aug", "precip": 3.98},
{"city": "Chicago", "month": "Dec", "precip": 2.56},
];