[Python] Use pandas merge_asof to achieve inexact left join

I have two pandas series:

right_series

Index​

Value
1​

0.1
2​

0.2
3​

0.3
6​

0.6
7​

0.7​

left_series

Index​

Value
1​

0.1
5​

0.5
10​

1.0​

I would like to join right_series on left_series by the indices, such that if an exact match of the index is not found, the nearest value is matched and the join behaves like a left join. Using pandas merge_asof in the following way

result = pd.merge_asof(left=left_series,right=right_series,left_index=True,right_index=True,direction="nearest")


yields

Left Index​

Left Value​

Right Value
1​

0.1​

0.1
5​

0.5​

0.6
10​

1.0​

0.7​

but I would like the lines with with right index 2 & 3 to also be matched (left index 2 to right index 1 and left index 3 to right index 1 or 5) and returned in the result, e.g.,

Left Index​

Left Value​

Right Value
1​

0.1​

0.1
1​

0.1​

0.2
1​

0.1​

0.3
5​

0.5​

0.6
10​

1.0​

0.7​

How can I best achieve this result?

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