>>> import decimal
>>> from snowflake.snowpark.types import StructField, VariantType
>>> df = session.create_dataframe([[decimal.Decimal(1), "X"]], schema=["a", "b"])
>>> df.select(is_decimal(to_variant(df["a"])).alias("decimal"), is_decimal(to_variant(df["b"])).alias("varchar")).collect()
[Row(DECIMAL=True, VARCHAR=False)]