Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/pandas/core/dtypes/astype.py

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+"""
+Functions for implementing 'astype' methods according to pandas conventions,
+particularly ones that differ from numpy.
+"""
+from __future__ import annotations
+
+import inspect
+from typing import (
+    TYPE_CHECKING,
+    overload,
+)
+import warnings
+
+import numpy as np
+
+from pandas._libs import lib
+from pandas._libs.tslibs.timedeltas import array_to_timedelta64
+from pandas.errors import IntCastingNaNError
+
+from pandas.core.dtypes.common import (
+    is_object_dtype,
+    is_string_dtype,
+    pandas_dtype,
+)
+from pandas.core.dtypes.dtypes import (
+    ExtensionDtype,
+    NumpyEADtype,
+)
+
+if TYPE_CHECKING:
+    from pandas._typing import (
+        ArrayLike,
+        DtypeObj,
+        IgnoreRaise,
+    )
+
+    from pandas.core.arrays import ExtensionArray
+
+_dtype_obj = np.dtype(object)
+
+
+@overload
+def _astype_nansafe(
+    arr: np.ndarray, dtype: np.dtype, copy: bool = ..., skipna: bool = ...
+) -> np.ndarray:
+    ...
+
+
+@overload
+def _astype_nansafe(
+    arr: np.ndarray, dtype: ExtensionDtype, copy: bool = ..., skipna: bool = ...
+) -> ExtensionArray:
+    ...
+
+
+def _astype_nansafe(
+    arr: np.ndarray, dtype: DtypeObj, copy: bool = True, skipna: bool = False
+) -> ArrayLike:
+    """
+    Cast the elements of an array to a given dtype a nan-safe manner.
+
+    Parameters
+    ----------
+    arr : ndarray
+    dtype : np.dtype or ExtensionDtype
+    copy : bool, default True
+        If False, a view will be attempted but may fail, if
+        e.g. the item sizes don't align.
+    skipna: bool, default False
+        Whether or not we should skip NaN when casting as a string-type.
+
+    Raises
+    ------
+    ValueError
+        The dtype was a datetime64/timedelta64 dtype, but it had no unit.
+    """
+
+    # dispatch on extension dtype if needed
+    if isinstance(dtype, ExtensionDtype):
+        return dtype.construct_array_type()._from_sequence(arr, dtype=dtype, copy=copy)
+
+    elif not isinstance(dtype, np.dtype):  # pragma: no cover
+        raise ValueError("dtype must be np.dtype or ExtensionDtype")
+
+    if arr.dtype.kind in "mM":
+        from pandas.core.construction import ensure_wrapped_if_datetimelike
+
+        arr = ensure_wrapped_if_datetimelike(arr)
+        res = arr.astype(dtype, copy=copy)
+        return np.asarray(res)
+
+    if issubclass(dtype.type, str):
+        shape = arr.shape
+        if arr.ndim > 1:
+            arr = arr.ravel()
+        return lib.ensure_string_array(
+            arr, skipna=skipna, convert_na_value=False
+        ).reshape(shape)
+
+    elif np.issubdtype(arr.dtype, np.floating) and dtype.kind in "iu":
+        return _astype_float_to_int_nansafe(arr, dtype, copy)
+
+    elif arr.dtype == object:
+        # if we have a datetime/timedelta array of objects
+        # then coerce to datetime64[ns] and use DatetimeArray.astype
+
+        if lib.is_np_dtype(dtype, "M"):
+            from pandas.core.arrays import DatetimeArray
+
+            dta = DatetimeArray._from_sequence(arr, dtype=dtype)
+            return dta._ndarray
+
+        elif lib.is_np_dtype(dtype, "m"):
+            from pandas.core.construction import ensure_wrapped_if_datetimelike
+
+            # bc we know arr.dtype == object, this is equivalent to
+            #  `np.asarray(to_timedelta(arr))`, but using a lower-level API that
+            #  does not require a circular import.
+            tdvals = array_to_timedelta64(arr).view("m8[ns]")
+
+            tda = ensure_wrapped_if_datetimelike(tdvals)
+            return tda.astype(dtype, copy=False)._ndarray
+
+    if dtype.name in ("datetime64", "timedelta64"):
+        msg = (
+            f"The '{dtype.name}' dtype has no unit. Please pass in "
+            f"'{dtype.name}[ns]' instead."
+        )
+        raise ValueError(msg)
+
+    if copy or arr.dtype == object or dtype == object:
+        # Explicit copy, or required since NumPy can't view from / to object.
+        return arr.astype(dtype, copy=True)
+
+    return arr.astype(dtype, copy=copy)
+
+
+def _astype_float_to_int_nansafe(
+    values: np.ndarray, dtype: np.dtype, copy: bool
+) -> np.ndarray:
+    """
+    astype with a check preventing converting NaN to an meaningless integer value.
+    """
+    if not np.isfinite(values).all():
+        raise IntCastingNaNError(
+            "Cannot convert non-finite values (NA or inf) to integer"
+        )
+    if dtype.kind == "u":
+        # GH#45151
+        if not (values >= 0).all():
+            raise ValueError(f"Cannot losslessly cast from {values.dtype} to {dtype}")
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore", category=RuntimeWarning)
+        return values.astype(dtype, copy=copy)
+
+
+def astype_array(values: ArrayLike, dtype: DtypeObj, copy: bool = False) -> ArrayLike:
+    """
+    Cast array (ndarray or ExtensionArray) to the new dtype.
+
+    Parameters
+    ----------
+    values : ndarray or ExtensionArray
+    dtype : dtype object
+    copy : bool, default False
+        copy if indicated
+
+    Returns
+    -------
+    ndarray or ExtensionArray
+    """
+    if values.dtype == dtype:
+        if copy:
+            return values.copy()
+        return values
+
+    if not isinstance(values, np.ndarray):
+        # i.e. ExtensionArray
+        values = values.astype(dtype, copy=copy)
+
+    else:
+        values = _astype_nansafe(values, dtype, copy=copy)
+
+    # in pandas we don't store numpy str dtypes, so convert to object
+    if isinstance(dtype, np.dtype) and issubclass(values.dtype.type, str):
+        values = np.array(values, dtype=object)
+
+    return values
+
+
+def astype_array_safe(
+    values: ArrayLike, dtype, copy: bool = False, errors: IgnoreRaise = "raise"
+) -> ArrayLike:
+    """
+    Cast array (ndarray or ExtensionArray) to the new dtype.
+
+    This basically is the implementation for DataFrame/Series.astype and
+    includes all custom logic for pandas (NaN-safety, converting str to object,
+    not allowing )
+
+    Parameters
+    ----------
+    values : ndarray or ExtensionArray
+    dtype : str, dtype convertible
+    copy : bool, default False
+        copy if indicated
+    errors : str, {'raise', 'ignore'}, default 'raise'
+        - ``raise`` : allow exceptions to be raised
+        - ``ignore`` : suppress exceptions. On error return original object
+
+    Returns
+    -------
+    ndarray or ExtensionArray
+    """
+    errors_legal_values = ("raise", "ignore")
+
+    if errors not in errors_legal_values:
+        invalid_arg = (
+            "Expected value of kwarg 'errors' to be one of "
+            f"{list(errors_legal_values)}. Supplied value is '{errors}'"
+        )
+        raise ValueError(invalid_arg)
+
+    if inspect.isclass(dtype) and issubclass(dtype, ExtensionDtype):
+        msg = (
+            f"Expected an instance of {dtype.__name__}, "
+            "but got the class instead. Try instantiating 'dtype'."
+        )
+        raise TypeError(msg)
+
+    dtype = pandas_dtype(dtype)
+    if isinstance(dtype, NumpyEADtype):
+        # Ensure we don't end up with a NumpyExtensionArray
+        dtype = dtype.numpy_dtype
+
+    try:
+        new_values = astype_array(values, dtype, copy=copy)
+    except (ValueError, TypeError):
+        # e.g. _astype_nansafe can fail on object-dtype of strings
+        #  trying to convert to float
+        if errors == "ignore":
+            new_values = values
+        else:
+            raise
+
+    return new_values
+
+
+def astype_is_view(dtype: DtypeObj, new_dtype: DtypeObj) -> bool:
+    """Checks if astype avoided copying the data.
+
+    Parameters
+    ----------
+    dtype : Original dtype
+    new_dtype : target dtype
+
+    Returns
+    -------
+    True if new data is a view or not guaranteed to be a copy, False otherwise
+    """
+    if isinstance(dtype, np.dtype) and not isinstance(new_dtype, np.dtype):
+        new_dtype, dtype = dtype, new_dtype
+
+    if dtype == new_dtype:
+        return True
+
+    elif isinstance(dtype, np.dtype) and isinstance(new_dtype, np.dtype):
+        # Only equal numpy dtypes avoid a copy
+        return False
+
+    elif is_string_dtype(dtype) and is_string_dtype(new_dtype):
+        # Potentially! a view when converting from object to string
+        return True
+
+    elif is_object_dtype(dtype) and new_dtype.kind == "O":
+        # When the underlying array has dtype object, we don't have to make a copy
+        return True
+
+    elif dtype.kind in "mM" and new_dtype.kind in "mM":
+        dtype = getattr(dtype, "numpy_dtype", dtype)
+        new_dtype = getattr(new_dtype, "numpy_dtype", new_dtype)
+        return getattr(dtype, "unit", None) == getattr(new_dtype, "unit", None)
+
+    numpy_dtype = getattr(dtype, "numpy_dtype", None)
+    new_numpy_dtype = getattr(new_dtype, "numpy_dtype", None)
+
+    if numpy_dtype is None and isinstance(dtype, np.dtype):
+        numpy_dtype = dtype
+
+    if new_numpy_dtype is None and isinstance(new_dtype, np.dtype):
+        new_numpy_dtype = new_dtype
+
+    if numpy_dtype is not None and new_numpy_dtype is not None:
+        # if both have NumPy dtype or one of them is a numpy dtype
+        # they are only a view when the numpy dtypes are equal, e.g.
+        # int64 -> Int64 or int64[pyarrow]
+        # int64 -> Int32 copies
+        return numpy_dtype == new_numpy_dtype
+
+    # Assume this is a view since we don't know for sure if a copy was made
+    return True