I have two DataFrames df_1
and df_2
are:
df_1 = pd.DataFrame({"A1":"1", "A2":"2", "A3":"3"}, index=[2411])
df_1.index.name = "i_1"
df_2 = pd.DataFrame({"B1":"4", "B2":"5", "B3":"6"}, index=[123122])
df_2.index.name = "i_2"
I want to concat them, so the final DataFrames will look like:
A1 A2 A3 B1 B2 B3
i_1 i_2
2411 123122 1 2 3 4 5 6
Basicly, that's concatination along axis 1 and mooving the setting a multi-index from indexes.
The most closest to the desired result, that i have done is:
df_1 = df_1.reset_index()
df_2 = df_2.reset_index()
df_f = pd.concat([df_1,df_2], axis=1)
df_f = pd.DataFrame(df_f, index=pd.MultiIndex.from_arrays([float(df_1["i_1"]), float(df_2["i_2"])], names=["i_1","i_2"]))
del df_f["i_1"]
del df_f["i_2"]
But the result is:
A1 A2 A3 B1 B2 B3
i_1 i_2
2411.0 123122.0 NaN NaN NaN NaN NaN NaN
I think simpliest is reset_index
of both df
for default indexes, so concat
align data nice and last set_index
:
df_f = pd.concat([df_1.reset_index(),df_2.reset_index()], axis=1).set_index(['i_1','i_2'])
print (df_f)
A1 A2 A3 B1 B2 B3
i_1 i_2
2411 123122 1 2 3 4 5 6
In you solution is problem different indexes, so after concat
get 2 rows, because data cannot allign (not same indexes):
df_f = pd.concat([df_1,df_2], axis=1)
print (df_f)
A1 A2 A3 B1 B2 B3
2411 1 2 3 NaN NaN NaN
123122 NaN NaN NaN 4 5 6
Then get NaN
s because in DataFrame
constructor create new Multiindex
but data not aligne again - in original df_f
are data size (2x6)
and want assign to 1,6
structure, also indexes are different.