utils.py 文件源码

def safe_eval(source):
    """
    Protected string evaluation.

    Evaluate a string containing a Python literal expression without
    allowing the execution of arbitrary non-literal code.

    Parameters
    ----------
    source : str
        The string to evaluate.

    Returns
    -------
    obj : object
       The result of evaluating `source`.

    Raises
    ------
    SyntaxError
        If the code has invalid Python syntax, or if it contains
        non-literal code.

    Examples
    --------
    >>> np.safe_eval('1')
    1
    >>> np.safe_eval('[1, 2, 3]')
    [1, 2, 3]
    >>> np.safe_eval('{"foo": ("bar", 10.0)}')
    {'foo': ('bar', 10.0)}

    >>> np.safe_eval('import os')
    Traceback (most recent call last):
      ...
    SyntaxError: invalid syntax

    >>> np.safe_eval('open("/home/user/.ssh/id_dsa").read()')
    Traceback (most recent call last):
      ...
    SyntaxError: Unsupported source construct: compiler.ast.CallFunc

    """
    # Local import to speed up numpy's import time.
    import ast

    return ast.literal_eval(source)
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