擅长:python、mysql、java
<p>你可以试试这样的</p>
<pre><code>from pandas.tseries.offsets import MonthEnd
import pandas as pd
df = pd.DataFrame({'Fecha': ['2020-01-31', '2020-02-29', '2020-03-31', '2020-05-31', '2020-04-30', '2020-07-31', '2020-06-30', '2020-08-31', '2020-09-30', '2020-10-31', '2020-11-30', '2020-12-31'],
'price': ['32132', '54321', '3213121', '432123', '32132', '54321', '32132', '54321', '3213121', '432123', '32132', '54321']})
df['Fecha'] = df['Fecha'].astype('datetime64[ns]')
df['is_month_end'] = df['Fecha'].dt.is_month_end
df = df[df['is_month_end'] == True]
df.sort_values('Fecha',inplace=True)
df.reset_index(drop=True, inplace = True)
def change(x,y):
try:
index = df[df['Fecha']==y].index.item()
last = df.loc[index-1][1]
return float(x)/float(last)
except:
return 0
df['new_column'] = df.apply(lambda row: change(row['price'],row['Fecha']), axis=1)
df.head(12)
</code></pre>