import pandas as pdpd.merge(dataframe1,dataframe2,on='common_field',how='outer') replace NaN dataframe1.fillna(0) #replace NaN to 0 transform from dataframe to Numpy array np.array(dataframe['column'])
import numpy as np #Create an array of 1*10^7 elements arr = np.arange(1e7) #Converting ndarray to list larr = arr.tolist() #Create a 2D numpy array arr = np.zeros((3,3)) #Converting a array to matrix mat = np.matrix(arr) np.matrix('1,2,3;4,5,6;7,8,9