[英]Randomly selecting rows from dataframe column by date
對於給定的 dataframe 列,我想按天隨機 select 大約 60% 並添加到新列中,將剩余的 40% 添加到另一列中,將 40% 列乘以 (-1),然后創建一個新列每天將這些重新合並在一起(這樣每天我的比例為 60/40) :
我在這里問了同樣的問題,但沒有每日規范: Randomly selection rows from dataframe column
下面的示例說明了這一點(盡管我的比率不完全是 60/40):
dict0 = {'date':[1/1/2019,1/1/2019,1/1/2019,1/2/2019,1/1/2019,1/2/2019],'x1': [1,2,3,4,5,6]}
df = pd.DataFrame(dict0)###
df['date'] = pd.to_datetime(df['date']).dt.date
dict1 = {'date':[1/1/2019,1/1/2019,1/1/2019,1/2/2019,1/1/2019,1/2/2019],'x1': [1,2,3,4,5,6],'x2': [1,'nan',3,'nan',5,6],'x3': ['nan',2,'nan',4,'nan','nan']}
df = pd.DataFrame(dict1)###
df['date'] = pd.to_datetime(df['date']).dt.date
dict2 = {'date':[1/1/2019,1/1/2019,1/1/2019,1/2/2019,1/1/2019,1/2/2019],'x1': [1,2,3,4,5,6],'x2': [1,'nan',3,'nan',5,6],'x3': ['nan',-2,'nan',-4,'nan','nan']}
df = pd.DataFrame(dict2)###
df['date'] = pd.to_datetime(df['date']).dt.date
dict3 = {'date':[1/1/2019,1/1/2019,1/1/2019,1/2/2019,1/1/2019,1/2/2019],'x1': [1,2,3,4,5,6],'x2': [1,'nan',3,'nan',5,6],'x3': ['nan',-2,'nan',- 4,'nan','nan'],'x4': [1,-2,3,-4,5,6]}
df = pd.DataFrame(dict3)###
df['date'] = pd.to_datetime(df['date']).dt.date
您可以使用groupby
和sample
,獲取index
值,然后使用 loc 創建列 x4,並使用 -1 相乘的列創建fillna
,例如:
idx= df.groupby('date').apply(lambda x: x.sample(frac=0.6)).index.get_level_values(1)
df.loc[idx, 'x4'] = df.loc[idx, 'x1']
df['x4'] = df['x4'].fillna(-df['x1'])
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.