Beispiel #1
0
def compile_condition(condition, typemap, indexedcols):
    """Compile a condition and extract usable index conditions.

    Looks for variable-constant comparisons in the `condition` string
    involving the indexed columns whose variable names appear in
    `indexedcols`.  The part of `condition` having usable indexes is
    returned as a compiled condition in a `CompiledCondition` container.

    Expressions such as '0 < c1 <= 1' do not work as expected.  The
    Numexpr types of *all* variables must be given in the `typemap`
    mapping.  The ``function`` of the resulting `CompiledCondition`
    instance is a Numexpr function object, and the ``parameters`` list
    indicates the order of its parameters.

    """

    # Get the expression tree and extract index conditions.
    expr = stringToExpression(condition, typemap, {})
    if expr.astKind != 'bool':
        raise TypeError("condition ``%s`` does not have a boolean type"
                        % condition)
    idxexprs = _get_idx_expr(expr, indexedcols)
    # Post-process the answer
    if isinstance(idxexprs, list):
        # Simple expression
        strexpr = ['e0']
    else:
        # Complex expression
        idxexprs, strexpr = idxexprs
    # Get rid of the unneccessary list wrapper for strexpr
    strexpr = strexpr[0]

    # Get the variable names used in the condition.
    # At the same time, build its signature.
    varnames = _get_variable_names(expr)
    signature = [(var, typemap[var]) for var in varnames]
    try:
        # See the comments in `numexpr.evaluate()` for the
        # reasons of inserting copy operators for unaligned,
        # *unidimensional* arrays.
        func = NumExpr(expr, signature)
    except NotImplementedError as nie:
        # Try to make this Numexpr error less cryptic.
        raise _unsupported_operation_error(nie)

    _, ex_uses_vml = getExprNames(condition, {})
    kwargs = {'ex_uses_vml': ex_uses_vml}

    params = varnames
    # This is more comfortable to handle about than a tuple.
    return CompiledCondition(func, params, idxexprs, strexpr, **kwargs)
Beispiel #2
0
def compile_condition(condition, typemap, indexedcols):
    """Compile a condition and extract usable index conditions.

    Looks for variable-constant comparisons in the `condition` string
    involving the indexed columns whose variable names appear in
    `indexedcols`.  The part of `condition` having usable indexes is
    returned as a compiled condition in a `CompiledCondition` container.

    Expressions such as '0 < c1 <= 1' do not work as expected.  The
    Numexpr types of *all* variables must be given in the `typemap`
    mapping.  The ``function`` of the resulting `CompiledCondition`
    instance is a Numexpr function object, and the ``parameters`` list
    indicates the order of its parameters.

    """

    # Get the expression tree and extract index conditions.
    expr = stringToExpression(condition, typemap, {})
    if expr.astKind != 'bool':
        raise TypeError("condition ``%s`` does not have a boolean type"
                        % condition)
    idxexprs = _get_idx_expr(expr, indexedcols)
    # Post-process the answer
    if isinstance(idxexprs, list):
        # Simple expression
        strexpr = ['e0']
    else:
        # Complex expression
        idxexprs, strexpr = idxexprs
    # Get rid of the unneccessary list wrapper for strexpr
    strexpr = strexpr[0]

    # Get the variable names used in the condition.
    # At the same time, build its signature.
    varnames = _get_variable_names(expr)
    signature = [(var, typemap[var]) for var in varnames]
    try:
        # See the comments in `numexpr.evaluate()` for the
        # reasons of inserting copy operators for unaligned,
        # *unidimensional* arrays.
        func = NumExpr(expr, signature)
    except NotImplementedError as nie:
        # Try to make this Numexpr error less cryptic.
        raise _unsupported_operation_error(nie)

    _, ex_uses_vml = getExprNames(condition, {})
    kwargs = {'ex_uses_vml': ex_uses_vml}

    params = varnames
    # This is more comfortable to handle about than a tuple.
    return CompiledCondition(func, params, idxexprs, strexpr, **kwargs)
Beispiel #3
0
def compile_condition(condition, typemap, indexedcols, copycols):
    """
    Compile a condition and extract usable index conditions.

    Looks for variable-constant comparisons in the `condition` string
    involving the indexed columns whose variable names appear in
    `indexedcols`.  The part of `condition` having usable indexes is
    returned as a compiled condition in a `CompiledCondition` container.

    Expressions such as '0 < c1 <= 1' do not work as expected.  The
    Numexpr types of *all* variables must be given in the `typemap`
    mapping.  The ``function`` of the resulting `CompiledCondition`
    instance is a Numexpr function object, and the ``parameters`` list
    indicates the order of its parameters.

    For columns whose variable names appear in `copycols`, an
    additional copy operation is inserted whenever the column is
    referenced.  This seems to accelerate access to unaligned,
    *unidimensional* arrays up to 2x (multidimensional arrays still
    need to be copied by `call_on_recarr()`.).
    """

    # Get the expression tree and extract index conditions.
    expr = stringToExpression(condition, typemap, {})
    if expr.astKind != 'bool':
        raise TypeError( "condition ``%s`` does not have a boolean type"
                         % condition )
    idxexprs = _get_idx_expr(expr, indexedcols)
    # Post-process the answer
    if type(idxexprs) == list:
        # Simple expression
        strexpr = ['e0']
    else:
        # Complex expression
        idxexprs, strexpr = idxexprs
    # Get rid of the unneccessary list wrapper for strexpr
    strexpr = strexpr[0]

    # Get the variable names used in the condition.
    # At the same time, build its signature.
    varnames = _get_variable_names(expr)
    signature = [(var, typemap[var]) for var in varnames]
    try:
        # See the comments in `numexpr.evaluate()` for the
        # reasons of inserting copy operators for unaligned,
        # *unidimensional* arrays.
        func = NumExpr(expr, signature, copy_args=copycols)
    except NotImplementedError, nie:
        # Try to make this Numexpr error less cryptic.
        raise _unsupported_operation_error(nie)
    def get_equation_variables(self, equation: str) -> Tuple[str, list]:
        """
        Converts an un-formatted equation to a more useable form,
        used to format values to variable places

        :return: Returns a tuple with the equation and the list of variables
        """

        # Find all variables from the equation given
        variables = list(map(
            lambda x: x.value,
            nec.typeCompileAst(
                nec.expressionToAST(
                    nec.stringToExpression(equation, {}, {})
                )
            ).allOf('variable')
        ))

        return variables