Cannot use median strategy with non-numeric data: could not convert string to float: ‘＜1

创建一个imputer实例, 指定你要用属性中的中位数替代该属性的缺失值，再使用fit()方法将imputer实例适配到训练集，实现代码如下：

from sklearn.impute import SimpleImputer
imputer = SimpleImputer(strategy='median')

imputer.fit(housing)

运行结果如下：

ValueError: Cannot use median strategy with non-numeric data:
could not convert string to