#Loading Libraries
import pandas as pd
import numpy as np
from sklearn.impute import KNNImputer

#Creating dataset
data = [[88, 21, np.nan,52], [32, 4,np.nan,71], 
      [12,np.nan, 62, 53], [np.nan,81, 38, 67]]

# Creating a KNNImputer object
imp = KNNImputer(n_neighbors=5, weights='uniform')

# Fitting transform
imputed_data=imp.fit_transform(data)

#Printing result
print(imputed_data)