merge / synchronize data frame using pandas [duplicate]

merge / synchronize 2 dataframes

dfA = {1.0001, 1.0003, 1.0005, 1.0007, 1.0009} # timestamp A
dfB = {1.0002, 1.0004, 1.0006, 1.0008, 1.0010} # timestamp B

can we merge / synchronize to something like this:

dfAB = {1.0001, 1.0002, 1.0003, 1.0004, 1.0005, 1.0006, 1.0007, 1.0008, 1.0009, 1.0010}

Assuming the values are timestamps in seconds.

Any pointers would help

NOTE: I have tried pd.merge but the result I get is:

dfAB = {1.0001, 1.0003, 1.0005, 1.0007, 1.0009,1.0002, 1.0004, 1.0006, 1.0008, 1.0010 }