SQLAlchemy equivalent to Active Record has_one_through -

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sqlalchemy's docs great little overwhelming @ times coming rails , active record.

given active record relationship set sqlalchemy equivalent establish relationship through intermediary table?

specifically given basic active record example below i'm trying understand how define equivalent relationship in sqlalchemy can allow account sqlalchemy model tied accounthistory model. i'm not clear if i'm supposed using mapper function , feel i'm missing simple in sqlalchemy.

class supplier < activerecord::base   has_one :account   has_one :account_history, through: :account end  class account < activerecord::base   belongs_to :supplier   has_one :account_history end  class accounthistory < activerecord::base   belongs_to :account end

perhaps misunderstood workings of has_one_through. in retrospect think looking this:

class supplier(base):     __tablename__ = 'supplier'     id = column(integer, primary_key=true)  class accounthistory(base):     __tablename__ = 'account_history'     id = column(integer, primary_key=true)     account_id = column(integer, foreignkey('account.id'))  class account(base):     __tablename__ = 'account'     supplier_id = column(integer, foreignkey('supplier.id'))

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