使用Pandas，如何按天对JSON数据进行分组并统计出现次数？

import pandas as pd
import json

with open('data.json') as f:
    data = json.load(f)

df = pd.DataFrame(data)

df['date'] = pd.to_datetime(df['date'])

df_grouped = df.groupby(df['date'].dt.date).size().reset_index(name='count')

print(df_grouped)