B = pd.DataFrame([[1, 1], [2, 2], [3, 3]], columns=['A', 'B'], index=[1, 2, 3])
C = pd.DataFrame([[1, 2], [1, 2], [1, 2]], columns=['A', 'B'], index=[1, 2, 3])
df_all = {'df1': A, 'df2': B, 'df3': C}
Looping through df dictionary in order to merge df's in Pandas