__init__.py

"""
Expose public exceptions & warnings
"""
from __future__ import annotations

import ctypes

from pandas._config.config import OptionError

from pandas._libs.tslibs import (
    OutOfBoundsDatetime,
    OutOfBoundsTimedelta,
)


class IntCastingNaNError(ValueError):
    """
    Exception raised when converting (``astype``) an array with NaN to an integer type.
    """


class NullFrequencyError(ValueError):
    """
    Exception raised when a ``freq`` cannot be null.

    Particularly ``DatetimeIndex.shift``, ``TimedeltaIndex.shift``,
    ``PeriodIndex.shift``.
    """


class PerformanceWarning(Warning):
    """
    Warning raised when there is a possible performance impact.
    """


class UnsupportedFunctionCall(ValueError):
    """
    Exception raised when attempting to call a unsupported numpy function.

    For example, ``np.cumsum(groupby_object)``.
    """


class UnsortedIndexError(KeyError):
    """
    Error raised when slicing a MultiIndex which has not been lexsorted.

    Subclass of `KeyError`.
    """


class ParserError(ValueError):
    """
    Exception that is raised by an error encountered in parsing file contents.

    This is a generic error raised for errors encountered when functions like
    `read_csv` or `read_html` are parsing contents of a file.

    See Also
    --------
    read_csv : Read CSV (comma-separated) file into a DataFrame.
    read_html : Read HTML table into a DataFrame.
    """


class DtypeWarning(Warning):
    """
    Warning raised when reading different dtypes in a column from a file.

    Raised for a dtype incompatibility. This can happen whenever `read_csv`
    or `read_table` encounter non-uniform dtypes in a column(s) of a given
    CSV file.

    See Also
    --------
    read_csv : Read CSV (comma-separated) file into a DataFrame.
    read_table : Read general delimited file into a DataFrame.

    Notes
    -----
    This warning is issued when dealing with larger files because the dtype
    checking happens per chunk read.

    Despite the warning, the CSV file is read with mixed types in a single
    column which will be an object type. See the examples below to better
    understand this issue.

    Examples
    --------
    This example creates and reads a large CSV file with a column that contains
    `int` and `str`.

    >>> df = pd.DataFrame({'a': (['1'] * 100000 + ['X'] * 100000 +
    ...                          ['1'] * 100000),
    ...                    'b': ['b'] * 300000})  # doctest: +SKIP
    >>> df.to_csv('test.csv', index=False)  # doctest: +SKIP
    >>> df2 = pd.read_csv('test.csv')  # doctest: +SKIP
    ... # DtypeWarning: Columns (0) have mixed types

    Important to notice that ``df2`` will contain both `str` and `int` for the
    same input, '1'.

    >>> df2.iloc[262140, 0]  # doctest: +SKIP
    '1'
    >>> type(df2.iloc[262140, 0])  # doctest: +SKIP
    <class 'str'>
    >>> df2.iloc[262150, 0]  # doctest: +SKIP
    1
    >>> type(df2.iloc[262150, 0])  # doctest: +SKIP
    <class 'int'>

    One way to solve this issue is using the `dtype` parameter in the
    `read_csv` and `read_table` functions to explicit the conversion:

    >>> df2 = pd.read_csv('test.csv', sep=',', dtype={'a': str})  # doctest: +SKIP

    No warning was issued.
    """


class EmptyDataError(ValueError):
    """
    Exception raised in ``pd.read_csv`` when empty data or header is encountered.
    """


class ParserWarning(Warning):
    """
    Warning raised when reading a file that doesn't use the default 'c' parser.

    Raised by `pd.read_csv` and `pd.read_table` when it is necessary to change
    parsers, generally from the default 'c' parser to 'python'.

    It happens due to a lack of support or functionality for parsing a
    particular attribute of a CSV file with the requested engine.

    Currently, 'c' unsupported options include the following parameters:

    1. `sep` other than a single character (e.g. regex separators)
    2. `skipfooter` higher than 0
    3. `sep=None` with `delim_whitespace=False`

    The warning can be avoided by adding `engine='python'` as a parameter in
    `pd.read_csv` and `pd.read_table` methods.

    See Also
    --------
    pd.read_csv : Read CSV (comma-separated) file into DataFrame.
    pd.read_table : Read general delimited file into DataFrame.

    Examples
    --------
    Using a `sep` in `pd.read_csv` other than a single character:

    >>> import io
    >>> csv = '''a;b;c
    ...           1;1,8
    ...           1;2,1'''
    >>> df = pd.read_csv(io.StringIO(csv), sep='[;,]')  # doctest: +SKIP
    ... # ParserWarning: Falling back to the 'python' engine...

    Adding `engine='python'` to `pd.read_csv` removes the Warning:

    >>> df = pd.read_csv(io.StringIO(csv), sep='[;,]', engine='python')
    """


class MergeError(ValueError):
    """
    Exception raised when merging data.

    Subclass of ``ValueError``.
    """


class AccessorRegistrationWarning(Warning):
    """
    Warning for attribute conflicts in accessor registration.
    """


class AbstractMethodError(NotImplementedError):
    """
    Raise this error instead of NotImplementedError for abstract methods.
    """

    def __init__(self, class_instance, methodtype: str = "method") -> None:
        types = {"method", "classmethod", "staticmethod", "property"}
        if methodtype not in types:
            raise ValueError(
                f"methodtype must be one of {methodtype}, got {types} instead."
            )
        self.methodtype = methodtype
        self.class_instance = class_instance

    def __str__(self) -> str:
        if self.methodtype == "classmethod":
            name = self.class_instance.__name__
        else:
            name = type(self.class_instance).__name__
        return f"This {self.methodtype} must be defined in the concrete class {name}"


class NumbaUtilError(Exception):
    """
    Error raised for unsupported Numba engine routines.
    """


class DuplicateLabelError(ValueError):
    """
    Error raised when an operation would introduce duplicate labels.

    .. versionadded:: 1.2.0

    Examples
    --------
    >>> s = pd.Series([0, 1, 2], index=['a', 'b', 'c']).set_flags(
    ...     allows_duplicate_labels=False
    ... )
    >>> s.reindex(['a', 'a', 'b'])
    Traceback (most recent call last):
       ...
    DuplicateLabelError: Index has duplicates.
          positions
    label
    a        [0, 1]
    """


class InvalidIndexError(Exception):
    """
    Exception raised when attempting to use an invalid index key.

    .. versionadded:: 1.1.0
    """


class DataError(Exception):
    """
    Exceptionn raised when performing an operation on non-numerical data.

    For example, calling ``ohlc`` on a non-numerical column or a function
    on a rolling window.
    """


class SpecificationError(Exception):
    """
    Exception raised by ``agg`` when the functions are ill-specified.

    The exception raised in two scenarios.

    The first way is calling ``agg`` on a
    Dataframe or Series using a nested renamer (dict-of-dict).

    The second way is calling ``agg`` on a Dataframe with duplicated functions
    names without assigning column name.

    Examples
    --------
    >>> df = pd.DataFrame({'A': [1, 1, 1, 2, 2],
    ...                    'B': range(5),
    ...                    'C': range(5)})
    >>> df.groupby('A').B.agg({'foo': 'count'}) # doctest: +SKIP
    ... # SpecificationError: nested renamer is not supported

    >>> df.groupby('A').agg({'B': {'foo': ['sum', 'max']}}) # doctest: +SKIP
    ... # SpecificationError: nested renamer is not supported

    >>> df.groupby('A').agg(['min', 'min']) # doctest: +SKIP
    ... # SpecificationError: nested renamer is not supported
    """


class SettingWithCopyError(ValueError):
    """
    Exception raised when trying to set on a copied slice from a ``DataFrame``.

    The ``mode.chained_assignment`` needs to be set to set to 'raise.' This can
    happen unintentionally when chained indexing.

    For more information on eveluation order,
    see :ref:`the user guide<indexing.evaluation_order>`.

    For more information on view vs. copy,
    see :ref:`the user guide<indexing.view_versus_copy>`.

    Examples
    --------
    >>> pd.options.mode.chained_assignment = 'raise'
    >>> df = pd.DataFrame({'A': [1, 1, 1, 2, 2]}, columns=['A'])
    >>> df.loc[0:3]['A'] = 'a' # doctest: +SKIP
    ... # SettingWithCopyError: A value is trying to be set on a copy of a...
    """


class SettingWithCopyWarning(Warning):
    """
    Warning raised when trying to set on a copied slice from a ``DataFrame``.

    The ``mode.chained_assignment`` needs to be set to set to 'warn.'
    'Warn' is the default option. This can happen unintentionally when
    chained indexing.

    For more information on eveluation order,
    see :ref:`the user guide<indexing.evaluation_order>`.

    For more information on view vs. copy,
    see :ref:`the user guide<indexing.view_versus_copy>`.

    Examples
    --------
    >>> df = pd.DataFrame({'A': [1, 1, 1, 2, 2]}, columns=['A'])
    >>> df.loc[0:3]['A'] = 'a' # doctest: +SKIP
    ... # SettingWithCopyWarning: A value is trying to be set on a copy of a...
    """


class NumExprClobberingError(NameError):
    """
    Exception raised when trying to use a built-in numexpr name as a variable name.

    ``eval`` or ``query`` will throw the error if the engine is set
    to 'numexpr'. 'numexpr' is the default engine value for these methods if the
    numexpr package is installed.

    Examples
    --------
    >>> df = pd.DataFrame({'abs': [1, 1, 1]})
    >>> df.query("abs > 2") # doctest: +SKIP
    ... # NumExprClobberingError: Variables in expression "(abs) > (2)" overlap...
    >>> sin, a = 1, 2
    >>> pd.eval("sin + a", engine='numexpr') # doctest: +SKIP
    ... # NumExprClobberingError: Variables in expression "(sin) + (a)" overlap...
    """


class UndefinedVariableError(NameError):
    """
    Exception raised by ``query`` or ``eval`` when using an undefined variable name.

    It will also specify whether the undefined variable is local or not.

    Examples
    --------
    >>> df = pd.DataFrame({'A': [1, 1, 1]})
    >>> df.query("A > x") # doctest: +SKIP
    ... # UndefinedVariableError: name 'x' is not defined
    >>> df.query("A > @y") # doctest: +SKIP
    ... # UndefinedVariableError: local variable 'y' is not defined
    >>> pd.eval('x + 1') # doctest: +SKIP
    ... # UndefinedVariableError: name 'x' is not defined
    """

    def __init__(self, name: str, is_local: bool | None = None) -> None:
        base_msg = f"{repr(name)} is not defined"
        if is_local:
            msg = f"local variable {base_msg}"
        else:
            msg = f"name {base_msg}"
        super().__init__(msg)


class IndexingError(Exception):
    """
    Exception is raised when trying to index and there is a mismatch in dimensions.

    Examples
    --------
    >>> df = pd.DataFrame({'A': [1, 1, 1]})
    >>> df.loc[..., ..., 'A'] # doctest: +SKIP
    ... # IndexingError: indexer may only contain one '...' entry
    >>> df = pd.DataFrame({'A': [1, 1, 1]})
    >>> df.loc[1, ..., ...] # doctest: +SKIP
    ... # IndexingError: Too many indexers
    >>> df[pd.Series([True], dtype=bool)] # doctest: +SKIP
    ... # IndexingError: Unalignable boolean Series provided as indexer...
    >>> s = pd.Series(range(2),
    ...               index = pd.MultiIndex.from_product([["a", "b"], ["c"]]))
    >>> s.loc["a", "c", "d"] # doctest: +SKIP
    ... # IndexingError: Too many indexers
    """


class PyperclipException(RuntimeError):
    """
    Exception raised when clipboard functionality is unsupported.

    Raised by ``to_clipboard()`` and ``read_clipboard()``.
    """


class PyperclipWindowsException(PyperclipException):
    """
    Exception raised when clipboard functionality is unsupported by Windows.

    Access to the clipboard handle would be denied due to some other
    window process is accessing it.
    """

    def __init__(self, message: str) -> None:
        # attr only exists on Windows, so typing fails on other platforms
        message += f" ({ctypes.WinError()})"  # type: ignore[attr-defined]
        super().__init__(message)


class CSSWarning(UserWarning):
    """
    Warning is raised when converting css styling fails.

    This can be due to the styling not having an equivalent value or because the
    styling isn't properly formatted.

    Examples
    --------
    >>> df = pd.DataFrame({'A': [1, 1, 1]})
    >>> df.style.applymap(lambda x: 'background-color: blueGreenRed;')
    ...         .to_excel('styled.xlsx') # doctest: +SKIP
    ... # CSSWarning: Unhandled color format: 'blueGreenRed'
    >>> df.style.applymap(lambda x: 'border: 1px solid red red;')
    ...         .to_excel('styled.xlsx') # doctest: +SKIP
    ... # CSSWarning: Too many tokens provided to "border" (expected 1-3)
    """


class PossibleDataLossError(Exception):
    """
    Exception raised when trying to open a HDFStore file when already opened.

    Examples
    --------
    >>> store = pd.HDFStore('my-store', 'a') # doctest: +SKIP
    >>> store.open("w") # doctest: +SKIP
    ... # PossibleDataLossError: Re-opening the file [my-store] with mode [a]...
    """


class ClosedFileError(Exception):
    """
    Exception is raised when trying to perform an operation on a closed HDFStore file.

    Examples
    --------
    >>> store = pd.HDFStore('my-store', 'a') # doctest: +SKIP
    >>> store.close() # doctest: +SKIP
    >>> store.keys() # doctest: +SKIP
    ... # ClosedFileError: my-store file is not open!
    """


class IncompatibilityWarning(Warning):
    """
    Warning raised when trying to use where criteria on an incompatible HDF5 file.
    """


class AttributeConflictWarning(Warning):
    """
    Warning raised when index attributes conflict when using HDFStore.

    Occurs when attempting to append an index with a different
    name than the existing index on an HDFStore or attempting to append an index with a
    different frequency than the existing index on an HDFStore.
    """


class DatabaseError(OSError):
    """
    Error is raised when executing sql with bad syntax or sql that throws an error.

    Examples
    --------
    >>> from sqlite3 import connect
    >>> conn = connect(':memory:')
    >>> pd.read_sql('select * test', conn) # doctest: +SKIP
    ... # DatabaseError: Execution failed on sql 'test': near "test": syntax error
    """


class DateTimeWarning(UserWarning):
    """
    Warning raised for issues with interpreting dates and times.
    """


__all__ = [
    "AbstractMethodError",
    "AccessorRegistrationWarning",
    "AttributeConflictWarning",
    "ClosedFileError",
    "CSSWarning",
    "DatabaseError",
    "DataError",
    "DateTimeWarning",
    "DtypeWarning",
    "DuplicateLabelError",
    "EmptyDataError",
    "IncompatibilityWarning",
    "IntCastingNaNError",
    "InvalidIndexError",
    "IndexingError",
    "MergeError",
    "NullFrequencyError",
    "NumbaUtilError",
    "NumExprClobberingError",
    "OptionError",
    "OutOfBoundsDatetime",
    "OutOfBoundsTimedelta",
    "ParserError",
    "ParserWarning",
    "PerformanceWarning",
    "PossibleDataLossError",
    "PyperclipException",
    "PyperclipWindowsException",
    "SettingWithCopyError",
    "SettingWithCopyWarning",
    "SpecificationError",
    "UndefinedVariableError",
    "UnsortedIndexError",
    "UnsupportedFunctionCall",
]