def write_to_version_file(filename, versions):
    """Write the given version number to the given _version.py file."""
    os.unlink(filename)
    contents = json.dumps(versions, sort_keys=True,
                          indent=1, separators=(",", ": "))
    with open(filename, "w") as f:
        f.write(SHORT_VERSION_PY % contents)

    print("set %s to '%s'" % (filename, versions["version"]))
Write the given version number to the given _version.py file.
versioneer.py