pandas to_datetime() then concat() on DateTime Index

Question

I\'m trying to merge 2 DataFrames using concat, on their DateTime Index, but it\'s not working as I expected. I copied some of this code from the example in the

Answer 1

pass axis=1 to concatenate column-wise:

In [7]:
pd.concat([df,df2], axis=1)

Out[7]:
            value    0
2015-02-04    444  222
2016-03-05    555  333

Alternatively you could've joined:

In [5]:
df.join(df2)

Out[5]:
            value    0
2015-02-04    444  222
2016-03-05    555  333

or merged:

In [8]:
df.merge(df2, left_index=True, right_index=True)

Out[8]:
            value    0
2015-02-04    444  222
2016-03-05    555  333