擅长:python、mysql、java
<p>计算加权平均温度。在TEMP中按位置填充缺少的日期,并将结果数据帧与DF合并。在</p>
<pre><code>TEMP.date = pd.to_datetime(TEMP.date)
TEMP = TEMP.groupby(['date', 'place']).apply(lambda x: np.round(np.average(x['temp'],weights=x['quantity']), 2)).reset_index(name = 'temp')
DF.merge(TEMP.set_index('date').groupby('place')['temp'].apply(lambda x: x.asfreq('D', method='ffill')).reset_index(), 'left')
date place temp
0 2019-01-01 A NaN
1 2019-01-11 A 5.00
2 2019-01-13 A 5.00
3 2019-01-14 A 7.00
4 2019-01-22 B 10.00
5 2019-02-14 C 10.75
</code></pre>