# NumPy 1.18.0 Release Notes¶

## New functions¶

### Multivariate hypergeometric distribution added to `numpy.random`

¶

The method *multivariate_hypergeometric* has been added to the class
`numpy.random.Generator`

. This method generates random variates from
the multivariate hypergeometric probability distribution.
(gh-13794)

## Deprecations¶

*np.fromfile* and *np.fromstring* will error on bad data¶

In future numpy releases, the functions *np.fromfile* and *np.fromstring*
will throw an error when parsing bad data.
This will now give a `DeprecationWarning`

where previously partial or
even invalid data was silently returned. This deprecation also affects
the C defined functions c:func:*PyArray_FromString`* and
c:func:*PyArray_FromFile*
(gh-13605)

### Deprecate *PyArray_As1D*, *PyArray_As2D*¶

*PyArray_As1D*, *PyArray_As2D* are deprecated, use
*PyArray_AsCArray* instead
(gh-14036)

### Deprecate the financial functions¶

In accordance with
NEP-32,
the functions *fv*, *ipmt*, *irr*, *mirr*, *nper*, *npv*, *pmt*, *ppmt*,
*pv* and *rate* are deprecated, and will be removed from NumPy 1.20.
The replacement for these functions is the Python package
numpy-financial.
(gh-14720)

## Expired deprecations¶

`PyArray_As1D`

and`PyArray_As2D`

have been removed in favor of`PyArray_AsCArray`

(gh-14036)`np.rank`

has been removed. This was deprecated in NumPy 1.10 and has been replaced by`np.ndim`

. (gh-14039)`PyArray_FromDimsAndDataAndDescr`

and`PyArray_FromDims`

have been removed (they will always raise an error). Use`PyArray_NewFromDescr`

and`PyArray_SimpleNew`

instead. (gh-14100)`numeric.loads`

,`numeric.load`

,`np.ma.dump`

,`np.ma.dumps`

,`np.ma.load`

,`np.ma.loads`

are removed, use`pickle`

methods instead (gh-14256)`arrayprint.FloatFormat`

,`arrayprint.LongFloatFormat`

has been removed, use`FloatingFormat`

instead`arrayprint.ComplexFormat`

,`arrayprint.LongComplexFormat`

has been removed, use`ComplexFloatingFormat`

instead`arrayprint.StructureFormat`

has been removed, use`StructureVoidFormat`

instead (gh-14259)`np.testing.rand`

has been removed. This was deprecated in NumPy 1.11 and has been replaced by`np.random.rand`

. (gh-14325)Class

`SafeEval`

in`numpy/lib/utils.py`

has been removed. This was deprecated in NumPy 1.10. Use`np.safe_eval`

instead. (gh-14335)Remove deprecated support for boolean and empty condition lists in

`numpy.select`

(gh-14583)Array order only accepts ‘C’, ‘F’, ‘A’, and ‘K’. More permissive options were deprecated in NumPy 1.11. (gh-14596)

np.linspace param num must be an integer. This was deprecated in NumPy 1.12. (gh-14620)

UFuncs with multiple outputs must use a tuple for the

*out*kwarg. This finishes a deprecation started in NumPy 1.10. (gh-14682)

The files `numpy/testing/decorators.py`

, `numpy/testing/noseclasses.py`

and `numpy/testing/nosetester.py`

have been removed. They were never
meant to be public (all relevant objects are present in the
`numpy.testing`

namespace), and importing them has given a deprecation
warning since NumPy 1.15.0
(gh-14567)

## Compatibility notes¶

`numpy.lib.recfunctions.drop_fields`

can no longer return None¶

If `drop_fields`

is used to drop all fields, previously the array would
be completely discarded and None returned. Now it returns an array of the
same shape as the input, but with no fields. The old behavior can be retained
with:

```
dropped_arr = drop_fields(arr, ['a', 'b'])
if dropped_arr.dtype.names == ():
dropped_arr = None
```

converting the empty recarray to None (gh-14510)

`numpy.argmin/argmax/min/max`

returns `NaT`

if it exists in array¶

`numpy.argmin`

, `numpy.argmax`

, `numpy.min`

, and `numpy.max`

will return
`NaT`

if it exists in the array.
(gh-14717)

### Changed random variate stream from `numpy.random.Generator.integers`

¶

There was a bug in `numpy.random.Generator.integers`

that caused biased
sampling of 8 and 16 bit integer types. Fixing that bug has changed the
output stream from what it was in previous releases.
(gh-14777)

### Add more ufunc loops for `datetime64`

, `timedelta64`

¶

`np.datetime('NaT')`

should behave more like `float('Nan')`

. Add needed
infrastructure so `np.isinf(a)`

and `np.isnan(a)`

will run on
`datetime64`

and `timedelta64`

dtypes. Also added specific loops for
`numpy.fmin`

and `numpy.fmax`

that mask `NaT`

. This may require adjustment to user-
facing code. Specifically, code that either disallowed the calls to
`numpy.isinf`

or `numpy.isnan`

or checked that they raised an exception will
require adaptation, and code that mistakenly called `numpy.fmax`

and
`numpy.fmin`

instead of `numpy.maximum`

or `numpy.minimum`

respectively will
requre adjustment. This also affects `numpy.nanmax`

and `numpy.nanmin`

.
(gh-14841)

## C API changes¶

## New Features¶

## Improvements¶

### Different C numeric types of the same size have unique names¶

On any given platform, two of `np.intc`

, `np.int_`

, and `np.longlong`

would previously appear indistinguishable through their `repr`

, despite
their corresponding `dtype`

having different properties.
A similar problem existed for the unsigned counterparts to these types, and on
some platforms for `np.double`

and `np.longdouble`

These types now always print with a unique `__name__`

.
(gh-10151)

`argwhere`

now produces a consistent result on 0d arrays¶

On N-d arrays, `numpy.argwhere`

now always produces an array of shape
`(n_non_zero, arr.ndim)`

, even when `arr.ndim == 0`

. Previously, the
last axis would have a dimension of 1 in this case.
(gh-13610)

### Add `axis`

argument for `random.permutation`

and `random.shuffle`

¶

Previously the `random.permutation`

and `random.shuffle`

functions
can only shuffle an array along the first axis; they now have a
new argument `axis`

which allows shuffle along a specified axis.
(gh-13829)

`method`

keyword argument for *np.random.multivariate_normal*¶

A `method`

keyword argument is now available for
*np.random.multivariate_normal* with possible values
`{'svd', 'eigh', 'cholesky'}`

. To use it, write
`np.random.multivariate_normal(..., method=<method>)`

.
(gh-14197)

### Add complex number support for `numpy.fromstring`

¶

Now `numpy.fromstring`

can read complex numbers.
(gh-14227)

`numpy.unique`

has consistent axes order (except the chosen one) when `axis`

is not None¶

Using `moveaxis`

instead of `swapaxes`

in `numpy.unique`

, so that the ordering of axes
except the axis in arguments will not be broken.
(gh-14255)

`numpy.matmul`

with boolean output now converts to boolean values¶

Calling `numpy.matmul`

where the output is a boolean array would fill the array
with uint8 equivalents of the result, rather than 0/1. Now it forces the output
to 0 or 1 (`NPY_TRUE`

or `NPY_FALSE`

).
(gh-14464)

`numpy.random.randint`

produced incorrect value when the range was `2**32`

¶

The implementation introduced in 1.17.0 had an incorrect check when
determining whether to use the 32-bit path or the full 64-bit
path that incorrectly redirected random integer generation with a high - low
range of `2**32`

to the 64-bit generator.
(gh-14501)

## Changes¶

### Incorrect `threshold`

in `np.set_printoptions`

raises `TypeError`

or `ValueError`

¶

Previously an incorrect `threshold`

raised `ValueError`

; it now raises `TypeError`

for non-numeric types and `ValueError`

for `nan`

values.
(gh-13899)

`numpy.distutils`

: append behavior changed for LDFLAGS and similar¶

`numpy.distutils`

has always overridden rather than appended to `LDFLAGS`

and
other similar such environment variables for compiling Fortran extensions. Now
the default behavior has changed to appending - which is the expected behavior
in most situations. To preserve the old (overwriting) behavior, set the
`NPY_DISTUTILS_APPEND_FLAGS`

environment variable to 0. This applies to:
`LDFLAGS`

, `F77FLAGS`

, `F90FLAGS`

, `FREEFLAGS`

, `FOPT`

, `FDEBUG`

,
and `FFLAGS`

. NumPy 1.16 and 1.17 gave build warnings in situations where this
change in behavior would have affected the compile flags used.
(gh-14248)

### Remove `numpy.random.entropy`

without a deprecation¶

`numpy.random.entropy`

was added to the `numpy.random`

namespace in 1.17.0.
It was meant to be a private c-extension module, but was exposed as public.
It has been replaced by `numpy.random.SeedSequence`

so the module was
completely removed.
(gh-14498)

### Add options to quiet build configuration and build with `-Werror`

¶

Added two new configuration options. During the `build_src`

subcommand, as
part of configuring NumPy, the files `_numpyconfig.h`

and `config.h`

are
created by probing support for various runtime functions and routines.
Previously, the very verbose compiler output during this stage clouded more
important information. By default the output is silenced. Running ```
runtests.py
--debug-info
```

will add `--verbose-cfg`

to the `build_src`

subcommand,
which will restore the previous behaviour.

Adding `CFLAGS=-Werror`

to turn warnings into errors would trigger errors
during the configuration. Now `runtests.py --warn-error`

will add
`--warn-error`

to the `build`

subcommand, which will percolate to the
`build_ext`

and `build_lib`

subcommands. This will add the compiler flag
to those stages and turn compiler warnings into errors while actually building
NumPy itself, avoiding the `build_src`

subcommand compiler calls.

The NumPy 1.18 release is currently in developement. Please check
the `numpy/doc/release/upcoming_changes/`

folder for upcoming
release notes.
The `numpy/doc/release/upcoming_changes/README.txt`

details how
to add new release notes.

For the work in progress release notes for the current development version, see the devdocs.