# What’s new in 0.23.2 (July 5, 2018)

This is a minor bug-fix release in the 0.23.x series and includes some small regression fixes and bug fixes. We recommend that all users upgrade to this version.

Note

Pandas 0.23.2 is first pandas release that’s compatible with Python 3.7 (GH20552)

Warning

Starting January 1, 2019, pandas feature releases will support Python 3 only. See Dropping Python 2.7 for more.

What’s new in v0.23.2

- Logical reductions over entire DataFrame
- Fixed regressions
- Build changes
- Bug fixes
- Contributors

## Logical reductions over entire DataFrame

`DataFrame.all()` and `DataFrame.any()` now accept `axis=None` to reduce over all axes to a scalar (GH19976)

    In [1]: df = pd.DataFrame({"A": [1, 2], "B": [True, False]})

    In [2]: df.all(axis=None)
    Out[2]: False

This also provides compatibility with NumPy 1.15, which now dispatches to `DataFrame.all`. With NumPy 1.15 and pandas 0.23.1 or earlier, `numpy.all()` will no longer reduce over every axis:

    >>> # NumPy 1.15, pandas 0.23.1
    >>> np.any(pd.DataFrame({"A": [False], "B": [False]}))
    A    False
    B    False
    dtype: bool

With pandas 0.23.2, that will correctly return False, as it did with NumPy < 1.15.

    In [3]: np.any(pd.DataFrame({"A": [False], "B": [False]}))
    Out[3]: False

## Fixed regressions

- Fixed regression in `to_csv()` when handling file-like object incorrectly (GH21471)
- Re-allowed duplicate level names of a `MultiIndex`. Accessing a level that has a duplicate name by name still raises an error (GH19029).
- Bug in both `DataFrame.first_valid_index()` and `Series.first_valid_index()` raised for a row index having duplicate values (GH21441)
- Fixed printing of DataFrames with hierarchical columns with long names (GH21180)
- Fixed regression in `reindex()` and `groupby()` with a MultiIndex or multiple keys that contains categorical datetime-like values (GH21390).
- Fixed regression in unary negative operations with object dtype (GH21380)
- Bug in `Timestamp.ceil()` and `Timestamp.floor()` when timestamp is a multiple of the rounding frequency (GH21262)
- Fixed regression in `to_clipboard()` that defaulted to copying dataframes with space delimited instead of tab delimited (GH21104)

## Build changes

- The source and binary distributions no longer include test data files, resulting in smaller download sizes. Tests relying on these data files will be skipped when using `pandas.test()`. (GH19320)

## Bug fixes

Conversion

- Bug in constructing `Index` with an iterator or generator (GH21470)
- Bug in `Series.nlargest()` for signed and unsigned integer dtypes when the minimum value is present (GH21426)

Indexing

- Bug in `Index.get_indexer_non_unique()` with categorical key (GH21448)
- Bug in comparison operations for `MultiIndex` where error was raised on equality / inequality comparison involving a MultiIndex with `nlevels == 1` (GH21149)
- Bug in `DataFrame.drop()` behaviour is not consistent for unique and non-unique indexes (GH21494)
- Bug in `DataFrame.duplicated()` with a large number of columns causing a ‘maximum recursion depth exceeded’ (GH21524).

I/O

- Bug in `read_csv()` that caused it to incorrectly raise an error when `nrows=0`, `low_memory=True`, and `index_col` was not `None` (GH21141)
- Bug in `json_normalize()` when formatting the `record_prefix` with integer columns (GH21536)

Categorical

- Bug in rendering `Series` with `Categorical` dtype in rare conditions under Python 2.7 (GH21002)

Timezones

- Bug in `Timestamp` and `DatetimeIndex` where passing a `Timestamp` localized after a DST transition would return a datetime before the DST transition (GH20854)
- Bug in comparing `DataFrame` with tz-aware `DatetimeIndex` columns with a DST transition that raised a `KeyError` (GH19970)
- Bug in `DatetimeIndex.shift()` where an `AssertionError` would raise when shifting across DST (GH8616)
- Bug in `Timestamp` constructor where passing an invalid timezone offset designator (`Z`) would not raise a `ValueError` (GH8910)
- Bug in `Timestamp.replace()` where replacing at a DST boundary would retain an incorrect offset (GH7825)
- Bug in `DatetimeIndex.reindex()` when reindexing a tz-naive and tz-aware `DatetimeIndex` (GH8306)
- Bug in `DatetimeIndex.resample()` when downsampling across a DST boundary (GH8531)

Timedelta

- Bug in `Timedelta` where non-zero timedeltas shorter than 1 microsecond were considered False (GH21484)

## Contributors

For contributors, please see /usr/share/doc/contributors_list.txt or https://github.com/pandas-dev/pandas/graphs/contributors
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