python/datafusion/__init__.py

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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
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"""DataFusion python package.

This is a Python library that binds to Apache Arrow in-memory query engine DataFusion.
See https://datafusion.apache.org/python for more information.
"""

try:
    import importlib.metadata as importlib_metadata
except ImportError:
    import importlib_metadata

from datafusion.col import col, column

from . import functions, object_store, substrait, unparser

# The following imports are okay to remain as opaque to the user.
from ._internal import Config
from .catalog import Catalog, Database, Table
from .common import (
    DFSchema,
)
from .context import (
    RuntimeEnvBuilder,
    SessionConfig,
    SessionContext,
    SQLOptions,
)
from .dataframe import DataFrame
from .expr import (
    Expr,
    WindowFrame,
)
from .html_formatter import configure_formatter
from .io import read_avro, read_csv, read_json, read_parquet
from .plan import ExecutionPlan, LogicalPlan
from .record_batch import RecordBatch, RecordBatchStream
from .udf import Accumulator, AggregateUDF, ScalarUDF, WindowUDF, udaf, udf, udwf

__version__ = importlib_metadata.version(__name__)

__all__ = [
    "Accumulator",
    "AggregateUDF",
    "Catalog",
    "Config",
    "DFSchema",
    "DataFrame",
    "Database",
    "ExecutionPlan",
    "Expr",
    "LogicalPlan",
    "RecordBatch",
    "RecordBatchStream",
    "RuntimeEnvBuilder",
    "SQLOptions",
    "ScalarUDF",
    "SessionConfig",
    "SessionContext",
    "Table",
    "WindowFrame",
    "WindowUDF",
    "col",
    "column",
    "common",
    "configure_formatter",
    "expr",
    "functions",
    "lit",
    "literal",
    "object_store",
    "read_avro",
    "read_csv",
    "read_json",
    "read_parquet",
    "substrait",
    "udaf",
    "udf",
    "udwf",
    "unparser",
]


def literal(value) -> Expr:
    """Create a literal expression."""
    return Expr.literal(value)


def string_literal(value):
    """Create a UTF8 literal expression.

    It differs from `literal` which creates a UTF8view literal.
    """
    return Expr.string_literal(value)


def str_lit(value):
    """Alias for `string_literal`."""
    return string_literal(value)


def lit(value) -> Expr:
    """Create a literal expression."""
    return Expr.literal(value)