import pandas as pd;
import numpy as np;

df1 = pd.DataFrame({'a': [10, 11, 12, 13], 'b': [20, 21, 22, 23]}, index = [0, 1, 2, 3]);
df2 = pd.DataFrame({'c': [32, 33, 34, 35], 'd': [42, 43, 44, 45]}, index = [2, 3, 4, 5]);

print(df1);
print(df2);

df3 = df2.join(df1,how='left');
print(df3);

df4 = pd.concat([df2,df1],axis=1);
print(df4);
import pandas as pd;
import numpy as np;

df1 = pd.DataFrame({'a': [10, 11, 12, 13], 'b': [20, 21, 22, 23]}, index = [0, 1, 2, 3]);
df2 = pd.DataFrame({'c': [32, 33, 34, 35], 'd': [42, 43, 44, 45]}, index = [2, 3, 4, 5]);

print(df1);
print(df2);

df3 = df2.join(df1,how='left');
print(df3);

df4 = pd.concat([df2,df1],axis=1);
print(df4);