如题
这是我的data frame
http://i.imgur.com/USqiil5.jpg
我想要把Death year字段资料为nan的变成0其他都变成1
import pandas as pd
mydata_csv = pd.read_csv('D:\Python\character-deaths.csv',sep = ',',encoding = 'utf-8')
mydata_csv
del mydata_csv['Book of Death']
del mydata_csv['Death Chapter']
if mydata_csv['Death Year'] == None:
mydata_csv['Death Year'] = 0
else:
mydata_csv['Death Year'] = 1
这个是我的程式码
到if那里就错误了QQ

也不说有什么错误讯息

import numpy as npif mydata_csv['Death Year'] == np.nan这样试试

ValueError: The truth value of a Series is ambiguous.Use a.empty, a.bool(), a.item(), a.any() or a.all().我改用 mydata_csv['Death Year'] = np.where(mydata_csv['Death Year']==None, 1, 0) 可以修改里面的资料了..但是通通变成0了QQ

np.where(pd.isnull(df['Death Year']), 0, 1)

goo.gl/xtV2SSpython里面np.nan跟np.nan不相等。本来dataframe里的也不是真的np.nan。不然直接用fillna试试其他用where不等于1取代。打错，适用fillna填上0，然后其他用不等于0 填上1

先确定pd里面的资料格式然后用最小单元（一格）先取代看看是否成功