Skip to content

BUG: Fix Index construction when given empty generator (#21470). #21481

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 8 commits into from
Jun 18, 2018
Merged

BUG: Fix Index construction when given empty generator (#21470). #21481

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
662eea2
BUG: Fix Index construction when given empty generator (#21470).
Liam3851 Jun 14, 2018
e470745
Fix trailing whitespace
Liam3851 Jun 14, 2018
bf81721
Don't nest if statements.
Liam3851 Jun 14, 2018
b0d9d2a
Fix CategoricalIndex constructor with iterator; test empty iterators.
Liam3851 Jun 14, 2018
254676c
Remove unused import.
Liam3851 Jun 15, 2018
ad2c0cb
Add whatsnew.
Liam3851 Jun 15, 2018
b2cf81f
Merge branch 'master' into PR_TOOL_MERGE_PR_21481
jreback Jun 18, 2018
650f810
doc
jreback Jun 18, 2018
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
10 changes: 6 additions & 4 deletions pandas/core/indexes/base.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -430,12 +430,14 @@ def __new__(cls, data=None, dtype=None, copy=False, name=None,
elif data is None or is_scalar(data):
cls._scalar_data_error(data)
else:
if tupleize_cols and is_list_like(data) and data:
if tupleize_cols and is_list_like(data):
# GH21470: convert iterable to list before determining if empty
if is_iterator(data):
data = list(data)
# we must be all tuples, otherwise don't construct
# 10697
if all(isinstance(e, tuple) for e in data):

if data and all(isinstance(e, tuple) for e in data):
# we must be all tuples, otherwise don't construct
# 10697
from .multi import MultiIndex
return MultiIndex.from_tuples(
data, names=name or kwargs.get('names'))
Expand Down
10 changes: 9 additions & 1 deletion pandas/tests/indexes/test_base.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -445,14 +445,22 @@ def test_constructor_dtypes_timedelta(self, attr, klass):
result = klass(list(values), dtype=dtype)
tm.assert_index_equal(result, index)

def test_constructor_empty_gen(self):
def test_constructor_empty_list(self):
Copy link
Member

@mroeschke mroeschke Jun 14, 2018 •
edited
Loading

Choose a reason for hiding this comment

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

Could you combine this test with the one below with pytest.mark.parametrize over skip_index_keys and the empty list and generator?

skip_index_keys = ["repeats", "periodIndex", "rangeIndex",
"tuples"]
for key, index in self.generate_index_types(skip_index_keys):
empty = index.__class__([])
assert isinstance(empty, index.__class__)
assert not len(empty)

def test_constructor_empty_gen(self):
skip_index_keys = ["repeats", "periodIndex", "rangeIndex",
"tuples"]
for key, index in self.generate_index_types(skip_index_keys):
empty = index.__class__(x for x in [])
assert isinstance(empty, index.__class__)
assert not len(empty)

@pytest.mark.parametrize("empty,klass", [
(PeriodIndex([], freq='B'), PeriodIndex),
(RangeIndex(step=1), pd.RangeIndex),
Expand Down