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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_value_format(value_format: Union[Callable, str] = str) -> Callable[[float], str]: """Create a formatting function from a generic value_format argument. """

    if value_format is None:
        value_format = ""
    if isinstance(value_format, str):
        format_str = "{0:" + value_format + "}"

        def value_format(x): return format_str.format(x)

    return value_format