def __init__(self, n_assets, tickers=None):
self.n_assets = n_assets<EOL>if tickers is None:<EOL><INDENT>self.tickers = list(range(n_assets))<EOL><DEDENT>else:<EOL><INDENT>self.tickers = tickers<EOL><DEDENT>self.weights = None<EOL>
:param n_assets: number of assets
:type n_assets: int
:param tickers: name of assets
:type tickers: list