| | |
| |
|
| | import ast |
| | from dataclasses import dataclass |
| | import operator as op |
| |
|
| |
|
| | from ._multiprocessing_helpers import mp |
| |
|
| | if mp is not None: |
| | from .externals.loky.process_executor import _ExceptionWithTraceback |
| |
|
| |
|
| | |
| | operators = { |
| | ast.Add: op.add, |
| | ast.Sub: op.sub, |
| | ast.Mult: op.mul, |
| | ast.Div: op.truediv, |
| | ast.FloorDiv: op.floordiv, |
| | ast.Mod: op.mod, |
| | ast.Pow: op.pow, |
| | ast.USub: op.neg, |
| | } |
| |
|
| |
|
| | def eval_expr(expr): |
| | """ |
| | >>> eval_expr('2*6') |
| | 12 |
| | >>> eval_expr('2**6') |
| | 64 |
| | >>> eval_expr('1 + 2*3**(4) / (6 + -7)') |
| | -161.0 |
| | """ |
| | try: |
| | return eval_(ast.parse(expr, mode="eval").body) |
| | except (TypeError, SyntaxError, KeyError) as e: |
| | raise ValueError( |
| | f"{expr!r} is not a valid or supported arithmetic expression." |
| | ) from e |
| |
|
| |
|
| | def eval_(node): |
| | if isinstance(node, ast.Constant): |
| | return node.value |
| | elif isinstance(node, ast.BinOp): |
| | return operators[type(node.op)](eval_(node.left), eval_(node.right)) |
| | elif isinstance(node, ast.UnaryOp): |
| | return operators[type(node.op)](eval_(node.operand)) |
| | else: |
| | raise TypeError(node) |
| |
|
| |
|
| | @dataclass(frozen=True) |
| | class _Sentinel: |
| | """A sentinel to mark a parameter as not explicitly set""" |
| | default_value: object |
| |
|
| | def __repr__(self): |
| | return f"default({self.default_value!r})" |
| |
|
| |
|
| | class _TracebackCapturingWrapper: |
| | """Protect function call and return error with traceback.""" |
| |
|
| | def __init__(self, func): |
| | self.func = func |
| |
|
| | def __call__(self, **kwargs): |
| | try: |
| | return self.func(**kwargs) |
| | except BaseException as e: |
| | return _ExceptionWithTraceback(e) |
| |
|
| |
|
| | def _retrieve_traceback_capturing_wrapped_call(out): |
| | if isinstance(out, _ExceptionWithTraceback): |
| | rebuild, args = out.__reduce__() |
| | out = rebuild(*args) |
| | if isinstance(out, BaseException): |
| | raise out |
| | return out |
| |
|