python/datafusion/col.py

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"""Col class."""

from datafusion.expr import Expr


class Col:
    """Create a column expression.

    This helper class allows an extra syntax of creating columns using the __getattr__
    method.
    """

    def __call__(self, value: str) -> Expr:
        """Create a column expression."""
        return Expr.column(value)

    def __getattr__(self, value: str) -> Expr:
        """Create a column using attribute syntax."""
        # For autocomplete to work with IPython
        if value.startswith("__wrapped__"):
            return getattr(type(self), value)

        return Expr.column(value)


col: Col = Col()
column: Col = Col()
__all__ = ["col", "column"]