组合是in和where

Question

如何根据Pandas中的奇偶标志创建新列

这是我的数据:

id   Flag
001   1
002   2
003   3
004   4

我想有这样的输出，如果标志是偶数则为雌性，如果标志是奇数则为雄性:

id   Flag   Gender
001   1     Male
002   2     Female
003   3     Male
004   4     Female

Answer 1

用numpy.where模2来检验偶数和奇数:

df['Gender'] = np.where(df['Flag'] % 2,'Male','Female')
print (df)
id  Flag  Gender
0   1     1    Male
1   2     2  Female
2   3     3    Male
3   4     4  Female

Answer 2

try apply

Id =['001','002','003','004']
Flag=[1,2,3,4]  
df=pd.DataFrame({'id':Id,'flag':Flag})
df['gender']=df['flag'].apply(lambda x: 'Male' if x%2 else 'Female')

输出:

id  flag  gender
0  001     1    Male
1  002     2  Female
2  003     3    Male
3  004     4  Female