Why do both insort_left and insort_right exist; isn't it always the same result since the elements are equal?
>>> import bisect
>>> foo = [1,2,3]
>>>
>>> bisect.insort_left(foo, 1)
>>> foo
[1, 1, 2, 3]
>>>
>>> bisect.insort_right(foo, 1)
>>> foo
[1, 1, 1, 2, 3]
Objects can be equivalent without being identical.
>>> bisect.insort_left(foo, 1.0)
>>> foo
[1.0, 1, 1, 1, 2, 3]
>>>
>>> bisect.insort_right(foo, 1.0)
>>> foo
[1.0, 1, 1, 1, 1.0, 2, 3]
For most purposes the results are indistinguishable, but there are cases where it can matter, particularly when using the optional key= argument.
Do you understand the difference between sorting algorithms that are, or aren't, guaranteed to be "stable"? If not, click the link ;-)
ys = []
for x in xs:
bisect.insort_right(ys, x)
fills ys with a stable sort of xs entries, but using insort_left() instead would not.