ENH: Add improved placeholder annotations for `np.ma`

4 files changed, 867 insertions, 224 deletions

diff --git a/numpy/ma/__init__.pyi b/numpy/ma/__init__.pyi
index 16e026272..a9a833e52 100644
--- a/numpy/ma/__init__.pyi
+++ b/numpy/ma/__init__.pyi
@@ -2,228 +2,231 @@ from typing import Any, List
 
 from numpy.ma import extras as extras
 
-__all__: List[str]
+from numpy.ma.core import (
+    MAError as MAError,
+    MaskError as MaskError,
+    MaskType as MaskType,
+    MaskedArray as MaskedArray,
+    abs as abs,
+    absolute as absolute,
+    add as add,
+    all as all,
+    allclose as allclose,
+    allequal as allequal,
+    alltrue as alltrue,
+    amax as amax,
+    amin as amin,
+    angle as angle,
+    anom as anom,
+    anomalies as anomalies,
+    any as any,
+    append as append,
+    arange as arange,
+    arccos as arccos,
+    arccosh as arccosh,
+    arcsin as arcsin,
+    arcsinh as arcsinh,
+    arctan as arctan,
+    arctan2 as arctan2,
+    arctanh as arctanh,
+    argmax as argmax,
+    argmin as argmin,
+    argsort as argsort,
+    around as around,
+    array as array,
+    asanyarray as asanyarray,
+    asarray as asarray,
+    bitwise_and as bitwise_and,
+    bitwise_or as bitwise_or,
+    bitwise_xor as bitwise_xor,
+    bool_ as bool_,
+    ceil as ceil,
+    choose as choose,
+    clip as clip,
+    common_fill_value as common_fill_value,
+    compress as compress,
+    compressed as compressed,
+    concatenate as concatenate,
+    conjugate as conjugate,
+    convolve as convolve,
+    copy as copy,
+    correlate as correlate,
+    cos as cos,
+    cosh as cosh,
+    count as count,
+    cumprod as cumprod,
+    cumsum as cumsum,
+    default_fill_value as default_fill_value,
+    diag as diag,
+    diagonal as diagonal,
+    diff as diff,
+    divide as divide,
+    empty as empty,
+    empty_like as empty_like,
+    equal as equal,
+    exp as exp,
+    expand_dims as expand_dims,
+    fabs as fabs,
+    filled as filled,
+    fix_invalid as fix_invalid,
+    flatten_mask as flatten_mask,
+    flatten_structured_array as flatten_structured_array,
+    floor as floor,
+    floor_divide as floor_divide,
+    fmod as fmod,
+    frombuffer as frombuffer,
+    fromflex as fromflex,
+    fromfunction as fromfunction,
+    getdata as getdata,
+    getmask as getmask,
+    getmaskarray as getmaskarray,
+    greater as greater,
+    greater_equal as greater_equal,
+    harden_mask as harden_mask,
+    hypot as hypot,
+    identity as identity,
+    ids as ids,
+    indices as indices,
+    inner as inner,
+    innerproduct as innerproduct,
+    isMA as isMA,
+    isMaskedArray as isMaskedArray,
+    is_mask as is_mask,
+    is_masked as is_masked,
+    isarray as isarray,
+    left_shift as left_shift,
+    less as less,
+    less_equal as less_equal,
+    log as log,
+    log10 as log10,
+    log2 as log2,
+    logical_and as logical_and,
+    logical_not as logical_not,
+    logical_or as logical_or,
+    logical_xor as logical_xor,
+    make_mask as make_mask,
+    make_mask_descr as make_mask_descr,
+    make_mask_none as make_mask_none,
+    mask_or as mask_or,
+    masked as masked,
+    masked_array as masked_array,
+    masked_equal as masked_equal,
+    masked_greater as masked_greater,
+    masked_greater_equal as masked_greater_equal,
+    masked_inside as masked_inside,
+    masked_invalid as masked_invalid,
+    masked_less as masked_less,
+    masked_less_equal as masked_less_equal,
+    masked_not_equal as masked_not_equal,
+    masked_object as masked_object,
+    masked_outside as masked_outside,
+    masked_print_option as masked_print_option,
+    masked_singleton as masked_singleton,
+    masked_values as masked_values,
+    masked_where as masked_where,
+    max as max,
+    maximum as maximum,
+    maximum_fill_value as maximum_fill_value,
+    mean as mean,
+    min as min,
+    minimum as minimum,
+    minimum_fill_value as minimum_fill_value,
+    mod as mod,
+    multiply as multiply,
+    mvoid as mvoid,
+    ndim as ndim,
+    negative as negative,
+    nomask as nomask,
+    nonzero as nonzero,
+    not_equal as not_equal,
+    ones as ones,
+    outer as outer,
+    outerproduct as outerproduct,
+    power as power,
+    prod as prod,
+    product as product,
+    ptp as ptp,
+    put as put,
+    putmask as putmask,
+    ravel as ravel,
+    remainder as remainder,
+    repeat as repeat,
+    reshape as reshape,
+    resize as resize,
+    right_shift as right_shift,
+    round as round,
+    round_ as round_,
+    set_fill_value as set_fill_value,
+    shape as shape,
+    sin as sin,
+    sinh as sinh,
+    size as size,
+    soften_mask as soften_mask,
+    sometrue as sometrue,
+    sort as sort,
+    sqrt as sqrt,
+    squeeze as squeeze,
+    std as std,
+    subtract as subtract,
+    sum as sum,
+    swapaxes as swapaxes,
+    take as take,
+    tan as tan,
+    tanh as tanh,
+    trace as trace,
+    transpose as transpose,
+    true_divide as true_divide,
+    var as var,
+    where as where,
+    zeros as zeros,
+)
+
+from numpy.ma.extras import (
+    apply_along_axis as apply_along_axis,
+    apply_over_axes as apply_over_axes,
+    atleast_1d as atleast_1d,
+    atleast_2d as atleast_2d,
+    atleast_3d as atleast_3d,
+    average as average,
+    clump_masked as clump_masked,
+    clump_unmasked as clump_unmasked,
+    column_stack as column_stack,
+    compress_cols as compress_cols,
+    compress_nd as compress_nd,
+    compress_rowcols as compress_rowcols,
+    compress_rows as compress_rows,
+    count_masked as count_masked,
+    corrcoef as corrcoef,
+    cov as cov,
+    diagflat as diagflat,
+    dot as dot,
+    dstack as dstack,
+    ediff1d as ediff1d,
+    flatnotmasked_contiguous as flatnotmasked_contiguous,
+    flatnotmasked_edges as flatnotmasked_edges,
+    hsplit as hsplit,
+    hstack as hstack,
+    isin as isin,
+    in1d as in1d,
+    intersect1d as intersect1d,
+    mask_cols as mask_cols,
+    mask_rowcols as mask_rowcols,
+    mask_rows as mask_rows,
+    masked_all as masked_all,
+    masked_all_like as masked_all_like,
+    median as median,
+    mr_ as mr_,
+    notmasked_contiguous as notmasked_contiguous,
+    notmasked_edges as notmasked_edges,
+    polyfit as polyfit,
+    row_stack as row_stack,
+    setdiff1d as setdiff1d,
+    setxor1d as setxor1d,
+    stack as stack,
+    unique as unique,
+    union1d as union1d,
+    vander as vander,
+    vstack as vstack,
+)
 
-core: Any
-extras: Any
-MAError: Any
-MaskError: Any
-MaskType: Any
-MaskedArray: Any
-abs: Any
-absolute: Any
-add: Any
-all: Any
-allclose: Any
-allequal: Any
-alltrue: Any
-amax: Any
-amin: Any
-angle: Any
-anom: Any
-anomalies: Any
-any: Any
-append: Any
-arange: Any
-arccos: Any
-arccosh: Any
-arcsin: Any
-arcsinh: Any
-arctan: Any
-arctan2: Any
-arctanh: Any
-argmax: Any
-argmin: Any
-argsort: Any
-around: Any
-array: Any
-asanyarray: Any
-asarray: Any
-bitwise_and: Any
-bitwise_or: Any
-bitwise_xor: Any
-bool_: Any
-ceil: Any
-choose: Any
-clip: Any
-common_fill_value: Any
-compress: Any
-compressed: Any
-concatenate: Any
-conjugate: Any
-convolve: Any
-copy: Any
-correlate: Any
-cos: Any
-cosh: Any
-count: Any
-cumprod: Any
-cumsum: Any
-default_fill_value: Any
-diag: Any
-diagonal: Any
-diff: Any
-divide: Any
-empty: Any
-empty_like: Any
-equal: Any
-exp: Any
-expand_dims: Any
-fabs: Any
-filled: Any
-fix_invalid: Any
-flatten_mask: Any
-flatten_structured_array: Any
-floor: Any
-floor_divide: Any
-fmod: Any
-frombuffer: Any
-fromflex: Any
-fromfunction: Any
-getdata: Any
-getmask: Any
-getmaskarray: Any
-greater: Any
-greater_equal: Any
-harden_mask: Any
-hypot: Any
-identity: Any
-ids: Any
-indices: Any
-inner: Any
-innerproduct: Any
-isMA: Any
-isMaskedArray: Any
-is_mask: Any
-is_masked: Any
-isarray: Any
-left_shift: Any
-less: Any
-less_equal: Any
-log: Any
-log10: Any
-log2: Any
-logical_and: Any
-logical_not: Any
-logical_or: Any
-logical_xor: Any
-make_mask: Any
-make_mask_descr: Any
-make_mask_none: Any
-mask_or: Any
-masked: Any
-masked_array: Any
-masked_equal: Any
-masked_greater: Any
-masked_greater_equal: Any
-masked_inside: Any
-masked_invalid: Any
-masked_less: Any
-masked_less_equal: Any
-masked_not_equal: Any
-masked_object: Any
-masked_outside: Any
-masked_print_option: Any
-masked_singleton: Any
-masked_values: Any
-masked_where: Any
-max: Any
-maximum: Any
-maximum_fill_value: Any
-mean: Any
-min: Any
-minimum: Any
-minimum_fill_value: Any
-mod: Any
-multiply: Any
-mvoid: Any
-ndim: Any
-negative: Any
-nomask: Any
-nonzero: Any
-not_equal: Any
-ones: Any
-outer: Any
-outerproduct: Any
-power: Any
-prod: Any
-product: Any
-ptp: Any
-put: Any
-putmask: Any
-ravel: Any
-remainder: Any
-repeat: Any
-reshape: Any
-resize: Any
-right_shift: Any
-round: Any
-round_: Any
-set_fill_value: Any
-shape: Any
-sin: Any
-sinh: Any
-size: Any
-soften_mask: Any
-sometrue: Any
-sort: Any
-sqrt: Any
-squeeze: Any
-std: Any
-subtract: Any
-sum: Any
-swapaxes: Any
-take: Any
-tan: Any
-tanh: Any
-trace: Any
-transpose: Any
-true_divide: Any
-var: Any
-where: Any
-zeros: Any
-apply_along_axis: Any
-apply_over_axes: Any
-atleast_1d: Any
-atleast_2d: Any
-atleast_3d: Any
-average: Any
-clump_masked: Any
-clump_unmasked: Any
-column_stack: Any
-compress_cols: Any
-compress_nd: Any
-compress_rowcols: Any
-compress_rows: Any
-count_masked: Any
-corrcoef: Any
-cov: Any
-diagflat: Any
-dot: Any
-dstack: Any
-ediff1d: Any
-flatnotmasked_contiguous: Any
-flatnotmasked_edges: Any
-hsplit: Any
-hstack: Any
-isin: Any
-in1d: Any
-intersect1d: Any
-mask_cols: Any
-mask_rowcols: Any
-mask_rows: Any
-masked_all: Any
-masked_all_like: Any
-median: Any
-mr_: Any
-notmasked_contiguous: Any
-notmasked_edges: Any
-polyfit: Any
-row_stack: Any
-setdiff1d: Any
-setxor1d: Any
-stack: Any
-unique: Any
-union1d: Any
-vander: Any
-vstack: Any
+__all__: List[str]
diff --git a/numpy/ma/core.pyi b/numpy/ma/core.pyi
new file mode 100644
index 000000000..e7e3f1f36
--- /dev/null
+++ b/numpy/ma/core.pyi
@@ -0,0 +1,468 @@
+from typing import Any, List, TypeVar, Callable
+from numpy import ndarray, dtype, float64
+
+from numpy import (
+    amax as amax,
+    amin as amin,
+    bool_ as bool_,
+    expand_dims as expand_dims,
+    diff as diff,
+    clip as clip,
+    indices as indices,
+    ones_like as ones_like,
+    squeeze as squeeze,
+    zeros_like as zeros_like,
+)
+
+from numpy.lib.function_base import (
+    angle as angle,
+)
+
+# TODO: Set the `bound` to something more suitable once we
+# have proper shape support
+_ShapeType = TypeVar("_ShapeType", bound=Any)
+_DType_co = TypeVar("_DType_co", bound=dtype[Any], covariant=True)
+
+__all__: List[str]
+
+MaskType = bool_
+nomask: bool_
+
+class MaskedArrayFutureWarning(FutureWarning): ...
+class MAError(Exception): ...
+class MaskError(MAError): ...
+
+def default_fill_value(obj): ...
+def minimum_fill_value(obj): ...
+def maximum_fill_value(obj): ...
+def set_fill_value(a, fill_value): ...
+def common_fill_value(a, b): ...
+def filled(a, fill_value=...): ...
+def getdata(a, subok=...): ...
+get_data = getdata
+
+def fix_invalid(a, mask=..., copy=..., fill_value=...): ...
+
+class _MaskedUFunc:
+    f: Any
+    __doc__: Any
+    __name__: Any
+    def __init__(self, ufunc): ...
+
+class _MaskedUnaryOperation(_MaskedUFunc):
+    fill: Any
+    domain: Any
+    def __init__(self, mufunc, fill=..., domain=...): ...
+    def __call__(self, a, *args, **kwargs): ...
+
+class _MaskedBinaryOperation(_MaskedUFunc):
+    fillx: Any
+    filly: Any
+    def __init__(self, mbfunc, fillx=..., filly=...): ...
+    def __call__(self, a, b, *args, **kwargs): ...
+    def reduce(self, target, axis=..., dtype=...): ...
+    def outer(self, a, b): ...
+    def accumulate(self, target, axis=...): ...
+
+class _DomainedBinaryOperation(_MaskedUFunc):
+    domain: Any
+    fillx: Any
+    filly: Any
+    def __init__(self, dbfunc, domain, fillx=..., filly=...): ...
+    def __call__(self, a, b, *args, **kwargs): ...
+
+exp: _MaskedUnaryOperation
+conjugate: _MaskedUnaryOperation
+sin: _MaskedUnaryOperation
+cos: _MaskedUnaryOperation
+arctan: _MaskedUnaryOperation
+arcsinh: _MaskedUnaryOperation
+sinh: _MaskedUnaryOperation
+cosh: _MaskedUnaryOperation
+tanh: _MaskedUnaryOperation
+abs: _MaskedUnaryOperation
+absolute: _MaskedUnaryOperation
+fabs: _MaskedUnaryOperation
+negative: _MaskedUnaryOperation
+floor: _MaskedUnaryOperation
+ceil: _MaskedUnaryOperation
+around: _MaskedUnaryOperation
+logical_not: _MaskedUnaryOperation
+sqrt: _MaskedUnaryOperation
+log: _MaskedUnaryOperation
+log2: _MaskedUnaryOperation
+log10: _MaskedUnaryOperation
+tan: _MaskedUnaryOperation
+arcsin: _MaskedUnaryOperation
+arccos: _MaskedUnaryOperation
+arccosh: _MaskedUnaryOperation
+arctanh: _MaskedUnaryOperation
+
+add: _MaskedBinaryOperation
+subtract: _MaskedBinaryOperation
+multiply: _MaskedBinaryOperation
+arctan2: _MaskedBinaryOperation
+equal: _MaskedBinaryOperation
+not_equal: _MaskedBinaryOperation
+less_equal: _MaskedBinaryOperation
+greater_equal: _MaskedBinaryOperation
+less: _MaskedBinaryOperation
+greater: _MaskedBinaryOperation
+logical_and: _MaskedBinaryOperation
+alltrue: _MaskedBinaryOperation
+logical_or: _MaskedBinaryOperation
+sometrue: Callable[..., Any]
+logical_xor: _MaskedBinaryOperation
+bitwise_and: _MaskedBinaryOperation
+bitwise_or: _MaskedBinaryOperation
+bitwise_xor: _MaskedBinaryOperation
+hypot: _MaskedBinaryOperation
+divide: _MaskedBinaryOperation
+true_divide: _MaskedBinaryOperation
+floor_divide: _MaskedBinaryOperation
+remainder: _MaskedBinaryOperation
+fmod: _MaskedBinaryOperation
+mod: _MaskedBinaryOperation
+
+def make_mask_descr(ndtype): ...
+def getmask(a): ...
+get_mask = getmask
+
+def getmaskarray(arr): ...
+def is_mask(m): ...
+def make_mask(m, copy=..., shrink=..., dtype=...): ...
+def make_mask_none(newshape, dtype=...): ...
+def mask_or(m1, m2, copy=..., shrink=...): ...
+def flatten_mask(mask): ...
+def masked_where(condition, a, copy=...): ...
+def masked_greater(x, value, copy=...): ...
+def masked_greater_equal(x, value, copy=...): ...
+def masked_less(x, value, copy=...): ...
+def masked_less_equal(x, value, copy=...): ...
+def masked_not_equal(x, value, copy=...): ...
+def masked_equal(x, value, copy=...): ...
+def masked_inside(x, v1, v2, copy=...): ...
+def masked_outside(x, v1, v2, copy=...): ...
+def masked_object(x, value, copy=..., shrink=...): ...
+def masked_values(x, value, rtol=..., atol=..., copy=..., shrink=...): ...
+def masked_invalid(a, copy=...): ...
+
+class _MaskedPrintOption:
+    def __init__(self, display): ...
+    def display(self): ...
+    def set_display(self, s): ...
+    def enabled(self): ...
+    def enable(self, shrink=...): ...
+
+masked_print_option: _MaskedPrintOption
+
+def flatten_structured_array(a): ...
+
+class MaskedIterator:
+    ma: Any
+    dataiter: Any
+    maskiter: Any
+    def __init__(self, ma): ...
+    def __iter__(self): ...
+    def __getitem__(self, indx): ...
+    def __setitem__(self, index, value): ...
+    def __next__(self): ...
+
+class MaskedArray(ndarray[_ShapeType, _DType_co]):
+    __array_priority__: Any
+    def __new__(cls, data=..., mask=..., dtype=..., copy=..., subok=..., ndmin=..., fill_value=..., keep_mask=..., hard_mask=..., shrink=..., order=...): ...
+    def __array_finalize__(self, obj): ...
+    def __array_wrap__(self, obj, context=...): ...
+    def view(self, dtype=..., type=..., fill_value=...): ...
+    def __getitem__(self, indx): ...
+    def __setitem__(self, indx, value): ...
+    @property
+    def dtype(self): ...
+    @dtype.setter
+    def dtype(self, dtype): ...
+    @property
+    def shape(self): ...
+    @shape.setter
+    def shape(self, shape): ...
+    def __setmask__(self, mask, copy=...): ...
+    @property
+    def mask(self): ...
+    @mask.setter
+    def mask(self, value): ...
+    @property
+    def recordmask(self): ...
+    @recordmask.setter
+    def recordmask(self, mask): ...
+    def harden_mask(self): ...
+    def soften_mask(self): ...
+    @property
+    def hardmask(self): ...
+    def unshare_mask(self): ...
+    @property
+    def sharedmask(self): ...
+    def shrink_mask(self): ...
+    @property
+    def baseclass(self): ...
+    data: Any
+    @property
+    def flat(self): ...
+    @flat.setter
+    def flat(self, value): ...
+    @property
+    def fill_value(self): ...
+    @fill_value.setter
+    def fill_value(self, value=...): ...
+    get_fill_value: Any
+    set_fill_value: Any
+    def filled(self, fill_value=...): ...
+    def compressed(self): ...
+    def compress(self, condition, axis=..., out=...): ...
+    def __eq__(self, other): ...
+    def __ne__(self, other): ...
+    def __add__(self, other): ...
+    def __radd__(self, other): ...
+    def __sub__(self, other): ...
+    def __rsub__(self, other): ...
+    def __mul__(self, other): ...
+    def __rmul__(self, other): ...
+    def __div__(self, other): ...
+    def __truediv__(self, other): ...
+    def __rtruediv__(self, other): ...
+    def __floordiv__(self, other): ...
+    def __rfloordiv__(self, other): ...
+    def __pow__(self, other): ...
+    def __rpow__(self, other): ...
+    def __iadd__(self, other): ...
+    def __isub__(self, other): ...
+    def __imul__(self, other): ...
+    def __idiv__(self, other): ...
+    def __ifloordiv__(self, other): ...
+    def __itruediv__(self, other): ...
+    def __ipow__(self, other): ...
+    def __float__(self): ...
+    def __int__(self): ...
+    @property  # type: ignore[misc]
+    def imag(self): ...
+    get_imag: Any
+    @property  # type: ignore[misc]
+    def real(self): ...
+    get_real: Any
+    def count(self, axis=..., keepdims=...): ...
+    def ravel(self, order=...): ...
+    def reshape(self, *s, **kwargs): ...
+    def resize(self, newshape, refcheck=..., order=...): ...
+    def put(self, indices, values, mode=...): ...
+    def ids(self): ...
+    def iscontiguous(self): ...
+    def all(self, axis=..., out=..., keepdims=...): ...
+    def any(self, axis=..., out=..., keepdims=...): ...
+    def nonzero(self): ...
+    def trace(self, offset=..., axis1=..., axis2=..., dtype=..., out=...): ...
+    def dot(self, b, out=..., strict=...): ...
+    def sum(self, axis=..., dtype=..., out=..., keepdims=...): ...
+    def cumsum(self, axis=..., dtype=..., out=...): ...
+    def prod(self, axis=..., dtype=..., out=..., keepdims=...): ...
+    product: Any
+    def cumprod(self, axis=..., dtype=..., out=...): ...
+    def mean(self, axis=..., dtype=..., out=..., keepdims=...): ...
+    def anom(self, axis=..., dtype=...): ...
+    def var(self, axis=..., dtype=..., out=..., ddof=..., keepdims=...): ...
+    def std(self, axis=..., dtype=..., out=..., ddof=..., keepdims=...): ...
+    def round(self, decimals=..., out=...): ...
+    def argsort(self, axis=..., kind=..., order=..., endwith=..., fill_value=...): ...
+    def argmin(self, axis=..., fill_value=..., out=...): ...
+    def argmax(self, axis=..., fill_value=..., out=...): ...
+    def sort(self, axis=..., kind=..., order=..., endwith=..., fill_value=...): ...
+    def min(self, axis=..., out=..., fill_value=..., keepdims=...): ...
+    # NOTE: deprecated
+    # def mini(self, axis=...): ...
+    # def tostring(self, fill_value=..., order=...): ...
+    def max(self, axis=..., out=..., fill_value=..., keepdims=...): ...
+    def ptp(self, axis=..., out=..., fill_value=..., keepdims=...): ...
+    def partition(self, *args, **kwargs): ...
+    def argpartition(self, *args, **kwargs): ...
+    def take(self, indices, axis=..., out=..., mode=...): ...
+    copy: Any
+    diagonal: Any
+    flatten: Any
+    repeat: Any
+    squeeze: Any
+    swapaxes: Any
+    T: Any
+    transpose: Any
+    def tolist(self, fill_value=...): ...
+    def tobytes(self, fill_value=..., order=...): ...
+    def tofile(self, fid, sep=..., format=...): ...
+    def toflex(self): ...
+    torecords: Any
+    def __reduce__(self): ...
+    def __deepcopy__(self, memo=...): ...
+
+class mvoid(MaskedArray[_ShapeType, _DType_co]):
+    def __new__(
+        self,
+        data,
+        mask=...,
+        dtype=...,
+        fill_value=...,
+        hardmask=...,
+        copy=...,
+        subok=...,
+    ): ...
+    def __getitem__(self, indx): ...
+    def __setitem__(self, indx, value): ...
+    def __iter__(self): ...
+    def __len__(self): ...
+    def filled(self, fill_value=...): ...
+    def tolist(self): ...
+
+def isMaskedArray(x): ...
+isarray = isMaskedArray
+isMA = isMaskedArray
+
+# 0D float64 array
+class MaskedConstant(MaskedArray[Any, dtype[float64]]):
+    def __new__(cls): ...
+    __class__: Any
+    def __array_finalize__(self, obj): ...
+    def __array_prepare__(self, obj, context=...): ...
+    def __array_wrap__(self, obj, context=...): ...
+    def __format__(self, format_spec): ...
+    def __reduce__(self): ...
+    def __iop__(self, other): ...
+    __iadd__: Any
+    __isub__: Any
+    __imul__: Any
+    __ifloordiv__: Any
+    __itruediv__: Any
+    __ipow__: Any
+    def copy(self, *args, **kwargs): ...
+    def __copy__(self): ...
+    def __deepcopy__(self, memo): ...
+    def __setattr__(self, attr, value): ...
+
+masked: MaskedConstant
+masked_singleton: MaskedConstant
+masked_array = MaskedArray
+
+def array(
+    data,
+    dtype=...,
+    copy=...,
+    order=...,
+    mask=...,
+    fill_value=...,
+    keep_mask=...,
+    hard_mask=...,
+    shrink=...,
+    subok=...,
+    ndmin=...,
+): ...
+def is_masked(x): ...
+
+class _extrema_operation(_MaskedUFunc):
+    compare: Any
+    fill_value_func: Any
+    def __init__(self, ufunc, compare, fill_value): ...
+    # NOTE: in practice `b` has a default value, but users should
+    # explicitly provide a value here as the default is deprecated
+    def __call__(self, a, b): ...
+    def reduce(self, target, axis=...): ...
+    def outer(self, a, b): ...
+
+def min(obj, axis=..., out=..., fill_value=..., keepdims=...): ...
+def max(obj, axis=..., out=..., fill_value=..., keepdims=...): ...
+def ptp(obj, axis=..., out=..., fill_value=..., keepdims=...): ...
+
+class _frommethod:
+    __name__: Any
+    __doc__: Any
+    reversed: Any
+    def __init__(self, methodname, reversed=...): ...
+    def getdoc(self): ...
+    def __call__(self, a, *args, **params): ...
+
+all: _frommethod
+anomalies: _frommethod
+anom: _frommethod
+any: _frommethod
+compress: _frommethod
+cumprod: _frommethod
+cumsum: _frommethod
+copy: _frommethod
+diagonal: _frommethod
+harden_mask: _frommethod
+ids: _frommethod
+mean: _frommethod
+nonzero: _frommethod
+prod: _frommethod
+product: _frommethod
+ravel: _frommethod
+repeat: _frommethod
+soften_mask: _frommethod
+std: _frommethod
+sum: _frommethod
+swapaxes: _frommethod
+trace: _frommethod
+var: _frommethod
+count: _frommethod
+argmin: _frommethod
+argmax: _frommethod
+
+minimum: _extrema_operation
+maximum: _extrema_operation
+
+def take(a, indices, axis=..., out=..., mode=...): ...
+def power(a, b, third=...): ...
+def argsort(a, axis=..., kind=..., order=..., endwith=..., fill_value=...): ...
+def sort(a, axis=..., kind=..., order=..., endwith=..., fill_value=...): ...
+def compressed(x): ...
+def concatenate(arrays, axis=...): ...
+def diag(v, k=...): ...
+def left_shift(a, n): ...
+def right_shift(a, n): ...
+def put(a, indices, values, mode=...): ...
+def putmask(a, mask, values): ...
+def transpose(a, axes=...): ...
+def reshape(a, new_shape, order=...): ...
+def resize(x, new_shape): ...
+def ndim(obj): ...
+def shape(obj): ...
+def size(obj, axis=...): ...
+def where(condition, x=..., y=...): ...
+def choose(indices, choices, out=..., mode=...): ...
+def round_(a, decimals=..., out=...): ...
+round = round_
+
+def inner(a, b): ...
+innerproduct = inner
+
+def outer(a, b): ...
+outerproduct = outer
+
+def correlate(a, v, mode=..., propagate_mask=...): ...
+def convolve(a, v, mode=..., propagate_mask=...): ...
+def allequal(a, b, fill_value=...): ...
+def allclose(a, b, masked_equal=..., rtol=..., atol=...): ...
+def asarray(a, dtype=..., order=...): ...
+def asanyarray(a, dtype=...): ...
+def fromflex(fxarray): ...
+
+class _convert2ma:
+    __doc__: Any
+    def __init__(self, funcname, params=...): ...
+    def getdoc(self): ...
+    def __call__(self, *args, **params): ...
+
+arange: _convert2ma
+empty: _convert2ma
+empty_like: _convert2ma
+frombuffer: _convert2ma
+fromfunction: _convert2ma
+identity: _convert2ma
+ones: _convert2ma
+zeros: _convert2ma
+
+def append(a, b, axis=...): ...
+def dot(a, b, strict=..., out=...): ...
+def mask_rowcols(a, axis=...): ...
diff --git a/numpy/ma/extras.pyi b/numpy/ma/extras.pyi
new file mode 100644
index 000000000..e58e43bad
--- /dev/null
+++ b/numpy/ma/extras.pyi
@@ -0,0 +1,84 @@
+from typing import Any, List
+from numpy.lib.index_tricks import AxisConcatenator
+
+from numpy.ma.core import (
+    dot as dot,
+    mask_rowcols as mask_rowcols,
+)
+
+__all__: List[str]
+
+def count_masked(arr, axis=...): ...
+def masked_all(shape, dtype = ...): ...
+def masked_all_like(arr): ...
+
+class _fromnxfunction:
+    __name__: Any
+    __doc__: Any
+    def __init__(self, funcname): ...
+    def getdoc(self): ...
+    def __call__(self, *args, **params): ...
+
+class _fromnxfunction_single(_fromnxfunction):
+    def __call__(self, x, *args, **params): ...
+
+class _fromnxfunction_seq(_fromnxfunction):
+    def __call__(self, x, *args, **params): ...
+
+class _fromnxfunction_allargs(_fromnxfunction):
+    def __call__(self, *args, **params): ...
+
+atleast_1d: _fromnxfunction_allargs
+atleast_2d: _fromnxfunction_allargs
+atleast_3d: _fromnxfunction_allargs
+
+vstack: _fromnxfunction_seq
+row_stack: _fromnxfunction_seq
+hstack: _fromnxfunction_seq
+column_stack: _fromnxfunction_seq
+dstack: _fromnxfunction_seq
+stack: _fromnxfunction_seq
+
+hsplit: _fromnxfunction_single
+diagflat: _fromnxfunction_single
+
+def apply_along_axis(func1d, axis, arr, *args, **kwargs): ...
+def apply_over_axes(func, a, axes): ...
+def average(a, axis=..., weights=..., returned=...): ...
+def median(a, axis=..., out=..., overwrite_input=..., keepdims=...): ...
+def compress_nd(x, axis=...): ...
+def compress_rowcols(x, axis=...): ...
+def compress_rows(a): ...
+def compress_cols(a): ...
+def mask_rows(a, axis = ...): ...
+def mask_cols(a, axis = ...): ...
+def ediff1d(arr, to_end=..., to_begin=...): ...
+def unique(ar1, return_index=..., return_inverse=...): ...
+def intersect1d(ar1, ar2, assume_unique=...): ...
+def setxor1d(ar1, ar2, assume_unique=...): ...
+def in1d(ar1, ar2, assume_unique=..., invert=...): ...
+def isin(element, test_elements, assume_unique=..., invert=...): ...
+def union1d(ar1, ar2): ...
+def setdiff1d(ar1, ar2, assume_unique=...): ...
+def cov(x, y=..., rowvar=..., bias=..., allow_masked=..., ddof=...): ...
+def corrcoef(x, y=..., rowvar=..., bias = ..., allow_masked=..., ddof = ...): ...
+
+class MAxisConcatenator(AxisConcatenator):
+    concatenate: Any
+    @classmethod
+    def makemat(cls, arr): ...
+    def __getitem__(self, key): ...
+
+class mr_class(MAxisConcatenator):
+    def __init__(self): ...
+
+mr_: mr_class
+
+def flatnotmasked_edges(a): ...
+def notmasked_edges(a, axis=...): ...
+def flatnotmasked_contiguous(a): ...
+def notmasked_contiguous(a, axis=...): ...
+def clump_unmasked(a): ...
+def clump_masked(a): ...
+def vander(x, n=...): ...
+def polyfit(x, y, deg, rcond=..., full=..., w=..., cov=...): ...
diff --git a/numpy/ma/mrecords.pyi b/numpy/ma/mrecords.pyi
new file mode 100644
index 000000000..92d5afb89
--- /dev/null
+++ b/numpy/ma/mrecords.pyi
@@ -0,0 +1,88 @@
+from typing import List, Any, TypeVar
+
+from numpy import dtype
+from numpy.ma import MaskedArray
+
+__all__: List[str]
+
+# TODO: Set the `bound` to something more suitable once we
+# have proper shape support
+_ShapeType = TypeVar("_ShapeType", bound=Any)
+_DType_co = TypeVar("_DType_co", bound=dtype[Any], covariant=True)
+
+class MaskedRecords(MaskedArray[_ShapeType, _DType_co]):
+    def __new__(
+        cls,
+        shape,
+        dtype=...,
+        buf=...,
+        offset=...,
+        strides=...,
+        formats=...,
+        names=...,
+        titles=...,
+        byteorder=...,
+        aligned=...,
+        mask=...,
+        hard_mask=...,
+        fill_value=...,
+        keep_mask=...,
+        copy=...,
+        **options,
+    ): ...
+    _mask: Any
+    _fill_value: Any
+    @property
+    def _data(self): ...
+    @property
+    def _fieldmask(self): ...
+    def __array_finalize__(self, obj): ...
+    def __len__(self): ...
+    def __getattribute__(self, attr): ...
+    def __setattr__(self, attr, val): ...
+    def __getitem__(self, indx): ...
+    def __setitem__(self, indx, value): ...
+    def view(self, dtype=..., type=...): ...
+    def harden_mask(self): ...
+    def soften_mask(self): ...
+    def copy(self): ...
+    def tolist(self, fill_value=...): ...
+    def __reduce__(self): ...
+
+mrecarray = MaskedRecords
+
+def fromarrays(
+    arraylist,
+    dtype=...,
+    shape=...,
+    formats=...,
+    names=...,
+    titles=...,
+    aligned=...,
+    byteorder=...,
+    fill_value=...,
+): ...
+
+def fromrecords(
+    reclist,
+    dtype=...,
+    shape=...,
+    formats=...,
+    names=...,
+    titles=...,
+    aligned=...,
+    byteorder=...,
+    fill_value=...,
+    mask=...,
+): ...
+
+def fromtextfile(
+    fname,
+    delimitor=...,
+    commentchar=...,
+    missingchar=...,
+    varnames=...,
+    vartypes=...,
+): ...
+
+def addfield(mrecord, newfield, newfieldname=...): ...