opt_einsum.contract.ContractExpression

class opt_einsum.contract.ContractExpression(contraction, contraction_list, constants_dict, **einsum_kwargs)

Helper class for storing an explicit contraction_list which can then be repeatedly called solely with the array arguments.

__init__(contraction, contraction_list, constants_dict, **einsum_kwargs)

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(contraction, contraction_list, …)	Initialize self.
evaluate_constants([backend])	Convert any constant operands to the correct backend form, and perform as many contractions as possible to create a new list of operands, stored in self._evaluated_constants[backend].

evaluate_constants(backend='auto')

Convert any constant operands to the correct backend form, and perform as many contractions as possible to create a new list of operands, stored in self._evaluated_constants[backend]. This also makes sure self.contraction_list only contains the remaining, non-const operations.