ai-content-maker/.venv/Lib/site-packages/pandas/core/common.py

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"""
Misc tools for implementing data structures
Note: pandas.core.common is *not* part of the public API.
"""
from __future__ import annotations
import builtins
from collections import (
abc,
defaultdict,
)
import contextlib
from functools import partial
import inspect
from typing import (
TYPE_CHECKING,
Any,
Callable,
Collection,
Hashable,
Iterable,
Iterator,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
AnyArrayLike,
ArrayLike,
NpDtype,
RandomState,
T,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.cast import construct_1d_object_array_from_listlike
from pandas.core.dtypes.common import (
is_array_like,
is_bool_dtype,
is_extension_array_dtype,
is_integer,
)
from pandas.core.dtypes.generic import (
ABCExtensionArray,
ABCIndex,
ABCSeries,
)
from pandas.core.dtypes.inference import iterable_not_string
from pandas.core.dtypes.missing import isna
if TYPE_CHECKING:
from pandas import Index
def flatten(line):
"""
Flatten an arbitrarily nested sequence.
Parameters
----------
line : sequence
The non string sequence to flatten
Notes
-----
This doesn't consider strings sequences.
Returns
-------
flattened : generator
"""
for element in line:
if iterable_not_string(element):
yield from flatten(element)
else:
yield element
def consensus_name_attr(objs):
name = objs[0].name
for obj in objs[1:]:
try:
if obj.name != name:
name = None
except ValueError:
name = None
return name
def is_bool_indexer(key: Any) -> bool:
"""
Check whether `key` is a valid boolean indexer.
Parameters
----------
key : Any
Only list-likes may be considered boolean indexers.
All other types are not considered a boolean indexer.
For array-like input, boolean ndarrays or ExtensionArrays
with ``_is_boolean`` set are considered boolean indexers.
Returns
-------
bool
Whether `key` is a valid boolean indexer.
Raises
------
ValueError
When the array is an object-dtype ndarray or ExtensionArray
and contains missing values.
See Also
--------
check_array_indexer : Check that `key` is a valid array to index,
and convert to an ndarray.
"""
if isinstance(key, (ABCSeries, np.ndarray, ABCIndex)) or (
is_array_like(key) and is_extension_array_dtype(key.dtype)
):
if key.dtype == np.object_:
key_array = np.asarray(key)
if not lib.is_bool_array(key_array):
na_msg = "Cannot mask with non-boolean array containing NA / NaN values"
if lib.infer_dtype(key_array) == "boolean" and isna(key_array).any():
# Don't raise on e.g. ["A", "B", np.nan], see
# test_loc_getitem_list_of_labels_categoricalindex_with_na
raise ValueError(na_msg)
return False
return True
elif is_bool_dtype(key.dtype):
return True
elif isinstance(key, list):
# check if np.array(key).dtype would be bool
if len(key) > 0:
if type(key) is not list:
# GH#42461 cython will raise TypeError if we pass a subclass
key = list(key)
return lib.is_bool_list(key)
return False
def cast_scalar_indexer(val, warn_float: bool = False):
"""
To avoid numpy DeprecationWarnings, cast float to integer where valid.
Parameters
----------
val : scalar
warn_float : bool, default False
If True, issue deprecation warning for a float indexer.
Returns
-------
outval : scalar
"""
# assumes lib.is_scalar(val)
if lib.is_float(val) and val.is_integer():
if warn_float:
warnings.warn(
"Indexing with a float is deprecated, and will raise an IndexError "
"in pandas 2.0. You can manually convert to an integer key instead.",
FutureWarning,
stacklevel=find_stack_level(),
)
return int(val)
return val
def not_none(*args):
"""
Returns a generator consisting of the arguments that are not None.
"""
return (arg for arg in args if arg is not None)
def any_none(*args) -> bool:
"""
Returns a boolean indicating if any argument is None.
"""
return any(arg is None for arg in args)
def all_none(*args) -> bool:
"""
Returns a boolean indicating if all arguments are None.
"""
return all(arg is None for arg in args)
def any_not_none(*args) -> bool:
"""
Returns a boolean indicating if any argument is not None.
"""
return any(arg is not None for arg in args)
def all_not_none(*args) -> bool:
"""
Returns a boolean indicating if all arguments are not None.
"""
return all(arg is not None for arg in args)
def count_not_none(*args) -> int:
"""
Returns the count of arguments that are not None.
"""
return sum(x is not None for x in args)
@overload
def asarray_tuplesafe(
values: ArrayLike | list | tuple | zip, dtype: NpDtype | None = ...
) -> np.ndarray:
# ExtensionArray can only be returned when values is an Index, all other iterables
# will return np.ndarray. Unfortunately "all other" cannot be encoded in a type
# signature, so instead we special-case some common types.
...
@overload
def asarray_tuplesafe(values: Iterable, dtype: NpDtype | None = ...) -> ArrayLike:
...
def asarray_tuplesafe(values: Iterable, dtype: NpDtype | None = None) -> ArrayLike:
if not (isinstance(values, (list, tuple)) or hasattr(values, "__array__")):
values = list(values)
elif isinstance(values, ABCIndex):
return values._values
if isinstance(values, list) and dtype in [np.object_, object]:
return construct_1d_object_array_from_listlike(values)
try:
with warnings.catch_warnings():
# Can remove warning filter once NumPy 1.24 is min version
warnings.simplefilter("ignore", np.VisibleDeprecationWarning)
result = np.asarray(values, dtype=dtype)
except ValueError:
# Using try/except since it's more performant than checking is_list_like
# over each element
# error: Argument 1 to "construct_1d_object_array_from_listlike"
# has incompatible type "Iterable[Any]"; expected "Sized"
return construct_1d_object_array_from_listlike(values) # type: ignore[arg-type]
if issubclass(result.dtype.type, str):
result = np.asarray(values, dtype=object)
if result.ndim == 2:
# Avoid building an array of arrays:
values = [tuple(x) for x in values]
result = construct_1d_object_array_from_listlike(values)
return result
def index_labels_to_array(
labels: np.ndarray | Iterable, dtype: NpDtype | None = None
) -> np.ndarray:
"""
Transform label or iterable of labels to array, for use in Index.
Parameters
----------
dtype : dtype
If specified, use as dtype of the resulting array, otherwise infer.
Returns
-------
array
"""
if isinstance(labels, (str, tuple)):
labels = [labels]
if not isinstance(labels, (list, np.ndarray)):
try:
labels = list(labels)
except TypeError: # non-iterable
labels = [labels]
labels = asarray_tuplesafe(labels, dtype=dtype)
return labels
def maybe_make_list(obj):
if obj is not None and not isinstance(obj, (tuple, list)):
return [obj]
return obj
def maybe_iterable_to_list(obj: Iterable[T] | T) -> Collection[T] | T:
"""
If obj is Iterable but not list-like, consume into list.
"""
if isinstance(obj, abc.Iterable) and not isinstance(obj, abc.Sized):
return list(obj)
obj = cast(Collection, obj)
return obj
def is_null_slice(obj) -> bool:
"""
We have a null slice.
"""
return (
isinstance(obj, slice)
and obj.start is None
and obj.stop is None
and obj.step is None
)
def is_true_slices(line) -> list[bool]:
"""
Find non-trivial slices in "line": return a list of booleans with same length.
"""
return [isinstance(k, slice) and not is_null_slice(k) for k in line]
# TODO: used only once in indexing; belongs elsewhere?
def is_full_slice(obj, line: int) -> bool:
"""
We have a full length slice.
"""
return (
isinstance(obj, slice)
and obj.start == 0
and obj.stop == line
and obj.step is None
)
def get_callable_name(obj):
# typical case has name
if hasattr(obj, "__name__"):
return getattr(obj, "__name__")
# some objects don't; could recurse
if isinstance(obj, partial):
return get_callable_name(obj.func)
# fall back to class name
if callable(obj):
return type(obj).__name__
# everything failed (probably because the argument
# wasn't actually callable); we return None
# instead of the empty string in this case to allow
# distinguishing between no name and a name of ''
return None
def apply_if_callable(maybe_callable, obj, **kwargs):
"""
Evaluate possibly callable input using obj and kwargs if it is callable,
otherwise return as it is.
Parameters
----------
maybe_callable : possibly a callable
obj : NDFrame
**kwargs
"""
if callable(maybe_callable):
return maybe_callable(obj, **kwargs)
return maybe_callable
def standardize_mapping(into):
"""
Helper function to standardize a supplied mapping.
Parameters
----------
into : instance or subclass of collections.abc.Mapping
Must be a class, an initialized collections.defaultdict,
or an instance of a collections.abc.Mapping subclass.
Returns
-------
mapping : a collections.abc.Mapping subclass or other constructor
a callable object that can accept an iterator to create
the desired Mapping.
See Also
--------
DataFrame.to_dict
Series.to_dict
"""
if not inspect.isclass(into):
if isinstance(into, defaultdict):
return partial(defaultdict, into.default_factory)
into = type(into)
if not issubclass(into, abc.Mapping):
raise TypeError(f"unsupported type: {into}")
elif into == defaultdict:
raise TypeError("to_dict() only accepts initialized defaultdicts")
return into
@overload
def random_state(state: np.random.Generator) -> np.random.Generator:
...
@overload
def random_state(
state: int | ArrayLike | np.random.BitGenerator | np.random.RandomState | None,
) -> np.random.RandomState:
...
def random_state(state: RandomState | None = None):
"""
Helper function for processing random_state arguments.
Parameters
----------
state : int, array-like, BitGenerator, Generator, np.random.RandomState, None.
If receives an int, array-like, or BitGenerator, passes to
np.random.RandomState() as seed.
If receives an np.random RandomState or Generator, just returns that unchanged.
If receives `None`, returns np.random.
If receives anything else, raises an informative ValueError.
.. versionchanged:: 1.1.0
array-like and BitGenerator object now passed to np.random.RandomState()
as seed
Default None.
Returns
-------
np.random.RandomState or np.random.Generator. If state is None, returns np.random
"""
if (
is_integer(state)
or is_array_like(state)
or isinstance(state, np.random.BitGenerator)
):
# error: Argument 1 to "RandomState" has incompatible type "Optional[Union[int,
# Union[ExtensionArray, ndarray[Any, Any]], Generator, RandomState]]"; expected
# "Union[None, Union[Union[_SupportsArray[dtype[Union[bool_, integer[Any]]]],
# Sequence[_SupportsArray[dtype[Union[bool_, integer[Any]]]]],
# Sequence[Sequence[_SupportsArray[dtype[Union[bool_, integer[Any]]]]]],
# Sequence[Sequence[Sequence[_SupportsArray[dtype[Union[bool_,
# integer[Any]]]]]]],
# Sequence[Sequence[Sequence[Sequence[_SupportsArray[dtype[Union[bool_,
# integer[Any]]]]]]]]], Union[bool, int, Sequence[Union[bool, int]],
# Sequence[Sequence[Union[bool, int]]], Sequence[Sequence[Sequence[Union[bool,
# int]]]], Sequence[Sequence[Sequence[Sequence[Union[bool, int]]]]]]],
# BitGenerator]"
return np.random.RandomState(state) # type: ignore[arg-type]
elif isinstance(state, np.random.RandomState):
return state
elif isinstance(state, np.random.Generator):
return state
elif state is None:
return np.random
else:
raise ValueError(
"random_state must be an integer, array-like, a BitGenerator, Generator, "
"a numpy RandomState, or None"
)
def pipe(
obj, func: Callable[..., T] | tuple[Callable[..., T], str], *args, **kwargs
) -> T:
"""
Apply a function ``func`` to object ``obj`` either by passing obj as the
first argument to the function or, in the case that the func is a tuple,
interpret the first element of the tuple as a function and pass the obj to
that function as a keyword argument whose key is the value of the second
element of the tuple.
Parameters
----------
func : callable or tuple of (callable, str)
Function to apply to this object or, alternatively, a
``(callable, data_keyword)`` tuple where ``data_keyword`` is a
string indicating the keyword of ``callable`` that expects the
object.
*args : iterable, optional
Positional arguments passed into ``func``.
**kwargs : dict, optional
A dictionary of keyword arguments passed into ``func``.
Returns
-------
object : the return type of ``func``.
"""
if isinstance(func, tuple):
func, target = func
if target in kwargs:
msg = f"{target} is both the pipe target and a keyword argument"
raise ValueError(msg)
kwargs[target] = obj
return func(*args, **kwargs)
else:
return func(obj, *args, **kwargs)
def get_rename_function(mapper):
"""
Returns a function that will map names/labels, dependent if mapper
is a dict, Series or just a function.
"""
def f(x):
if x in mapper:
return mapper[x]
else:
return x
return f if isinstance(mapper, (abc.Mapping, ABCSeries)) else mapper
def convert_to_list_like(
values: Hashable | Iterable | AnyArrayLike,
) -> list | AnyArrayLike:
"""
Convert list-like or scalar input to list-like. List, numpy and pandas array-like
inputs are returned unmodified whereas others are converted to list.
"""
if isinstance(values, (list, np.ndarray, ABCIndex, ABCSeries, ABCExtensionArray)):
return values
elif isinstance(values, abc.Iterable) and not isinstance(values, str):
return list(values)
return [values]
@contextlib.contextmanager
def temp_setattr(obj, attr: str, value) -> Iterator[None]:
"""Temporarily set attribute on an object.
Args:
obj: Object whose attribute will be modified.
attr: Attribute to modify.
value: Value to temporarily set attribute to.
Yields:
obj with modified attribute.
"""
old_value = getattr(obj, attr)
setattr(obj, attr, value)
try:
yield obj
finally:
setattr(obj, attr, old_value)
def require_length_match(data, index: Index) -> None:
"""
Check the length of data matches the length of the index.
"""
if len(data) != len(index):
raise ValueError(
"Length of values "
f"({len(data)}) "
"does not match length of index "
f"({len(index)})"
)
# the ufuncs np.maximum.reduce and np.minimum.reduce default to axis=0,
# whereas np.min and np.max (which directly call obj.min and obj.max)
# default to axis=None.
_builtin_table = {
builtins.sum: np.sum,
builtins.max: np.maximum.reduce,
builtins.min: np.minimum.reduce,
}
_cython_table = {
builtins.sum: "sum",
builtins.max: "max",
builtins.min: "min",
np.all: "all",
np.any: "any",
np.sum: "sum",
np.nansum: "sum",
np.mean: "mean",
np.nanmean: "mean",
np.prod: "prod",
np.nanprod: "prod",
np.std: "std",
np.nanstd: "std",
np.var: "var",
np.nanvar: "var",
np.median: "median",
np.nanmedian: "median",
np.max: "max",
np.nanmax: "max",
np.min: "min",
np.nanmin: "min",
np.cumprod: "cumprod",
np.nancumprod: "cumprod",
np.cumsum: "cumsum",
np.nancumsum: "cumsum",
}
def get_cython_func(arg: Callable) -> str | None:
"""
if we define an internal function for this argument, return it
"""
return _cython_table.get(arg)
def is_builtin_func(arg):
"""
if we define a builtin function for this argument, return it,
otherwise return the arg
"""
return _builtin_table.get(arg, arg)
def fill_missing_names(names: Sequence[Hashable | None]) -> list[Hashable]:
"""
If a name is missing then replace it by level_n, where n is the count
.. versionadded:: 1.4.0
Parameters
----------
names : list-like
list of column names or None values.
Returns
-------
list
list of column names with the None values replaced.
"""
return [f"level_{i}" if name is None else name for i, name in enumerate(names)]
def resolve_numeric_only(numeric_only: bool | None | lib.NoDefault) -> bool:
"""Determine the Boolean value of numeric_only.
See GH#46560 for details on the deprecation.
Parameters
----------
numeric_only : bool, None, or lib.no_default
Value passed to the method.
Returns
-------
Resolved value of numeric_only.
"""
if numeric_only is lib.no_default:
# Methods that behave like numeric_only=True and only got the numeric_only
# arg in 1.5.0 default to lib.no_default
result = True
elif numeric_only is None:
# Methods that had the numeric_only arg prior to 1.5.0 and try all columns
# first default to None
result = False
else:
result = numeric_only
return result
def deprecate_numeric_only_default(
cls: type, name: str, deprecate_none: bool = False
) -> None:
"""Emit FutureWarning message for deprecation of numeric_only.
See GH#46560 for details on the deprecation.
Parameters
----------
cls : type
pandas type that is generating the warning.
name : str
Name of the method that is generating the warning.
deprecate_none : bool, default False
Whether to also warn about the deprecation of specifying ``numeric_only=None``.
"""
if name in ["all", "any"]:
arg_name = "bool_only"
else:
arg_name = "numeric_only"
msg = (
f"The default value of {arg_name} in {cls.__name__}.{name} is "
"deprecated. In a future version, it will default to False. "
)
if deprecate_none:
msg += f"In addition, specifying '{arg_name}=None' is deprecated. "
msg += (
f"Select only valid columns or specify the value of {arg_name} to silence "
"this warning."
)
warnings.warn(msg, FutureWarning, stacklevel=find_stack_level())