done

lib/python3.11/site-packages/narwhals/exceptions.py

@@ -0,0 +1,108 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Collection, Iterable
+
+
+class NarwhalsError(ValueError):
+    """Base class for all Narwhals exceptions."""
+
+
+class FormattedKeyError(KeyError):
+    """KeyError with formatted error message.
+
+    Python's `KeyError` has special casing around formatting
+    (see https://bugs.python.org/issue2651). Use this class when the error
+    message has newlines and other special format characters.
+    Needed by https://github.com/tensorflow/tensorflow/issues/36857.
+    """
+
+    def __init__(self, message: str) -> None:
+        self.message = message
+
+    def __str__(self) -> str:
+        return self.message
+
+
+class ColumnNotFoundError(FormattedKeyError, NarwhalsError):
+    """Exception raised when column name isn't present."""
+
+    def __init__(self, message: str) -> None:
+        self.message = message
+        super().__init__(self.message)
+
+    @classmethod
+    def from_missing_and_available_column_names(
+        cls, missing_columns: Iterable[str], available_columns: Collection[str], /
+    ) -> ColumnNotFoundError:
+        message = (
+            f"The following columns were not found: {sorted(missing_columns)}"
+            f"\n\nHint: Did you mean one of these columns: {list(available_columns)}?"
+        )
+        return ColumnNotFoundError(message)
+
+    @classmethod
+    def from_available_column_names(
+        cls, available_columns: Collection[str]
+    ) -> ColumnNotFoundError:
+        message = (
+            "The selected columns were not found."
+            f"\n\nHint: Did you mean one of these columns: {list(available_columns)}?"
+        )
+        return ColumnNotFoundError(message)
+
+
+class ComputeError(NarwhalsError):
+    """Exception raised when the underlying computation could not be evaluated."""
+
+
+class ShapeError(NarwhalsError):
+    """Exception raised when trying to perform operations on data structures with incompatible shapes."""
+
+
+class MultiOutputExpressionError(NarwhalsError):
+    """Exception raised when using multi-output expression in unsupported context."""
+
+
+class DuplicateError(NarwhalsError):
+    """Exception when duplicate column names are encountered."""
+
+
+class InvalidOperationError(NarwhalsError):
+    """Exception raised during invalid operations."""
+
+
+class InvalidIntoExprError(TypeError, NarwhalsError):
+    """Exception raised when object can't be converted to expression."""
+
+    def __init__(self, message: str) -> None:
+        self.message = message
+        super().__init__(self.message)
+
+    @classmethod
+    def from_invalid_type(cls: type, invalid_type: type) -> InvalidIntoExprError:
+        message = (
+            f"Expected an object which can be converted into an expression, got {invalid_type}\n\n"
+            "Hint:\n"
+            "- if you were trying to select a column which does not have a string\n"
+            "  column name, then you should explicitly use `nw.col`.\n"
+            "  For example, `df.select(nw.col(0))` if you have a column named `0`.\n"
+            "- if you were trying to create a new literal column, then you \n"
+            "  should explicitly use `nw.lit`.\n"
+            "  For example, `df.select(nw.lit(0))` if you want to create a new\n"
+            "  column with literal value `0`."
+        )
+        return InvalidIntoExprError(message)
+
+
+class UnsupportedDTypeError(NarwhalsError):
+    """Exception raised when trying to convert to a DType which is not supported by the given backend."""
+
+
+class NarwhalsUnstableWarning(UserWarning):
+    """Warning issued when a method or function is considered unstable in the stable api."""
+
+
+class PerformanceWarning(Warning): ...