Confusing (possibly buggy) IntervalIndex behavior

In the above, I have a region that I’m querying for with a partially overlapping interval. The query succeeds when the interval is partially overlapping until it doesn’t, throwing the key error:

KeyError                                  Traceback (most recent call last)
/Users/alex/Documents/GarNet/venv/lib/python3.6/site-packages/pandas/core/indexing.py in _has_valid_type(self, key, axis)
   1433                 if not ax.contains(key):
-> 1434                     error()
   1435             except TypeError as e:

/Users/alex/Documents/GarNet/venv/lib/python3.6/site-packages/pandas/core/indexing.py in error()
   1428                 raise KeyError("the label [%s] is not in the [%s]" %
-> 1429                                (key, self.obj._get_axis_name(axis)))
   1430 

KeyError: 'the label [(5409951, 5409965]] is not in the [index]'

I think this is particularly confusing because there doesn’t seem to be any prominent difference between the locs that succeed and the loc that fails as far as I can tell. I know we had discussed loc’s behavior in this context but I’m not sure we came to a conclusion.

By the way, my larger question is about how to find intersections between two IntervalIndex. It seems like the find_intersections function didn’t make it into this release @jreback ? Let me know! =]

[buyology]

chiming in on this, as we are heavy users of postgres range types and range operators as a powerful abstraction for time series data

as already been mentioned, the key verbs are contains and overlaps both on element and range level and in both directions:

examples from the postgres docs:

Operator	Description	Example	Result
@>	contains range	int4range(2,4) @> int4range(2,3)	t
@>	contains element	'[2011-01-01,2011-03-01)'::tsrange @> '2011-01-10'::timestamp	t
<@	range is contained by	int4range(2,4) <@ int4range(1,7)	t
<@	element is contained by	42 <@ int4range(1,7)	f
&&	overlap (have points in common)	int8range(3,7) && int8range(4,12)	t
<<	strictly left of	int8range(1,10) << int8range(100,110)	t
-|-	is adjacent to	numrange(1.1,2.2) -|- numrange(2.2,3.3)	t

now that we have Intervals in pandas (very grateful for bringing that feature @jreback!) I have already tinkered around with some mappers for going between Postgres and pandas — maybe that is too db-specific but def have a great interest in seeing more Interval type functionality in Pandas and helping out with this

[jreback]

came across this library: https://github.com/AlexandreDecan/python-intervals

looks to have some interesting interval semantics

cc @jschendel