Skip to content

BUG: Hashtable size hint cap #22805

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 7 commits into from
Jan 15, 2019
Merged

BUG: Hashtable size hint cap #22805

Show file tree
Hide file tree
Changes from 5 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
0dc5f4b
wip
Sep 21, 2018
33f665a
remaining cases
chris-b1 Sep 22, 2018
cf947de
Merge remote-tracking branch 'upstream/master' into size-hint-cap
Dec 12, 2018
74b3b45
whatsnew
Dec 12, 2018
f2c4a1b
lint
Dec 12, 2018
d154b07
type ctor parameter
Dec 13, 2018
d3cbb2b
Merge remote-tracking branch 'upstream/master' into size-hint-cap
Jan 14, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions doc/source/whatsnew/v0.24.0.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1539,6 +1539,7 @@ Groupby/Resample/Rolling
- Bug in :meth:`pandas.core.groupby.DataFrameGroupBy.rank` with ``method='dense'`` and ``pct=True`` when a group has only one member would raise a ``ZeroDivisionError`` (:issue:`23666`).
- Calling :meth:`DataFrameGroupBy.rank` and :meth:`SeriesGroupBy.rank` with empty groups and ``pct=True`` was raising a ``ZeroDivisionError`` due to `c1068d9 <https://github.com/pandas-dev/pandas/commit/c1068d9d242c22cb2199156f6fb82eb5759178ae>`_ (:issue:`22519`)
- Bug in :meth:`DataFrame.resample` when resampling ``NaT`` in ``TimeDeltaIndex`` (:issue:`13223`).
- Bug preventing hash table creation with very large number (2^32) of rows (:issue:`22805`)

Reshaping
^^^^^^^^^
Expand Down
8 changes: 6 additions & 2 deletions pandas/_libs/hashtable_class_helper.pxi.in
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -265,6 +265,7 @@ cdef class {{name}}HashTable(HashTable):
def __cinit__(self, size_hint=1):
self.table = kh_init_{{dtype}}()
if size_hint is not None:
size_hint = min(size_hint, _SIZE_HINT_LIMIT)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

you can type the size_hint as a uint_t I think to avoid this problem

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

It's getting typed as a uint on the next line - we actually want it untyped here so it could accept arbitrarily large values, just needs capped before before being converted to the c-type (what was causing the original error)

kh_resize_{{dtype}}(self.table, size_hint)

def __len__(self):
Expand Down Expand Up @@ -573,9 +574,10 @@ cdef class StringHashTable(HashTable):
# or a sentinel np.nan / None missing value
na_string_sentinel = '__nan__'

def __init__(self, int size_hint=1):
def __init__(self, size_hint=1):
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

can you just type this as int64?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

good point, that'll work

self.table = kh_init_str()
if size_hint is not None:
size_hint = min(size_hint, _SIZE_HINT_LIMIT)
kh_resize_str(self.table, size_hint)

def __dealloc__(self):
Expand Down Expand Up @@ -878,7 +880,9 @@ cdef class PyObjectHashTable(HashTable):

def __init__(self, size_hint=1):
self.table = kh_init_pymap()
kh_resize_pymap(self.table, size_hint)
if size_hint is not None:
size_hint = min(size_hint, _SIZE_HINT_LIMIT)
kh_resize_pymap(self.table, size_hint)

def __dealloc__(self):
if self.table is not NULL:
Expand Down
8 changes: 8 additions & 0 deletions pandas/tests/test_algos.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1405,6 +1405,14 @@ def test_hashtable_factorize(self, htable, tm_dtype, writable):
expected_reconstruct = s_duplicated.dropna().values
tm.assert_numpy_array_equal(result_reconstruct, expected_reconstruct)

@pytest.mark.parametrize('hashtable', [
ht.PyObjectHashTable, ht.StringHashTable,
ht.Float64HashTable, ht.Int64HashTable, ht.UInt64HashTable])
def test_hashtable_large_sizehint(self, hashtable):
# GH 22729
size_hint = np.iinfo(np.uint32).max + 1
tbl = hashtable(size_hint=size_hint) # noqa


def test_quantile():
s = Series(np.random.randn(100))
Expand Down