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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 _paths_from_env(variable: str, default: List[Path]) -> List[Path]: """Read an environment variable as a list of paths. The environment variable with the specified name is read, and its value split on colons and returned as a list of paths. If the environment variable is not set, or set to the empty string, the default value is returned. Parameters variable : str Name of the environment variable. default : List[Path] Default value. Returns ------- List[Path] Value from environment or default. """

    # TODO(srstevenson): Use assignment expression in Python 3.8.
    value = os.environ.get(variable)
    if value:
        return [Path(path) for path in value.split(":")]
    return default