main.py 文件源码

def __init__(self):
        if not is_pyethereum21_available():
            version = get_pyethereum_version()
            if version is None:
                raise pkg_resources.DistributionNotFound(
                    "The `ethereum` package is not available.  The "
                    "`PyEthereum21Backend` requires a 2.0.0+ version of the "
                    "ethereum package to be installed."
                )
            elif version not in Spec('>=2.0.0,<2.2.0'):
                raise pkg_resources.DistributionNotFound(
                    "The `PyEthereum21Backend` requires a 2.0.0+ version of the "
                    "`ethereum` package.  Found {0}".format(version)
                )
        self.reset_to_genesis()

    #
    # Fork block numbers
    #