摘要：
import numpy as np import pandas as pd df1=pd.DataFrame(np.ones((3,4))*0,columns=['a','b','c','d']) df2=pd.DataFrame(np.ones((3,4))*1,columns=['a','b','c','d']) df3=pd.DataFrame(np.ones((3,4))*2,colu... 阅读全文
摘要：
import pandas as pd data = {'state': ['Ohio', 'Ohio', 'Ohio', 'Nevada', 'Nevada'],'year': [2000, 2001, 2002, 2001, 2002],'pop': [1.5, 1.7, 3.6, 2.4, 2.9]} # 建立DataFrame对象 frame1 = pd.DataFrame(data)... 阅读全文