两表拼接 pd.concat

a = pd.DataFrame([[1,2,3],
                  [4,5,6],
                  [7,8,9]],columns=['a','b','c'])
b = pd.DataFrame([[11,23,45],
                  [22,23,24],
                  [31,32,33]],columns=['a','b','c'])
pd.concat([a,b],axis=0,ignore_index=True)