datafusion/tests/test_imports.py

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import pytest

import datafusion
from datafusion import (
    AggregateUDF,
    DataFrame,
    SessionContext,
    ScalarUDF,
    functions,
)

from datafusion.common import (
    DFField,
    DFSchema,
)

from datafusion.expr import (
    Expr,
    Column,
    Literal,
    BinaryExpr,
    AggregateFunction,
    Projection,
    TableScan,
    Filter,
    Limit,
    Aggregate,
    Sort,
    Analyze,
)


def test_import_datafusion():
    assert datafusion.__name__ == "datafusion"


def test_datafusion_python_version():
    assert datafusion.__version__ is not None


def test_class_module_is_datafusion():
    for klass in [
        SessionContext,
        DataFrame,
        ScalarUDF,
        AggregateUDF,
    ]:
        assert klass.__module__ == "datafusion"

    # expressions
    for klass in [Expr, Column, Literal, BinaryExpr, AggregateFunction]:
        assert klass.__module__ == "datafusion.expr"

    # operators
    for klass in [
        Projection,
        TableScan,
        Aggregate,
        Sort,
        Limit,
        Filter,
        Analyze,
    ]:
        assert klass.__module__ == "datafusion.expr"

    # schema
    for klass in [DFField, DFSchema]:
        assert klass.__module__ == "datafusion.common"


def test_import_from_functions_submodule():
    from datafusion.functions import abs, sin  # noqa

    assert functions.abs is abs
    assert functions.sin is sin

    msg = "cannot import name 'foobar' from 'datafusion.functions'"
    with pytest.raises(ImportError, match=msg):
        from datafusion.functions import foobar  # noqa


def test_classes_are_inheritable():
    class MyExecContext(SessionContext):
        pass

    class MyExpression(Expr):
        pass

    class MyDataFrame(DataFrame):
        pass