coo_matrix initializer

coo.py

class coo_matrix(_data_matrix, _minmax_mixin):
    ...
    
    format = 'coo'

    def __init__(self, arg1, shape=None, dtype=None, copy=False):
        _data_matrix.__init__(self)

        if isinstance(arg1, tuple):
            ...

        else:
            if isspmatrix(arg1):
                ...
            else:
                #dense argument
                M = np.atleast_2d(np.asarray(arg1))

                if M.ndim != 2:
                    raise TypeError('expected dimension <= 2 array or matrix')
                else:
                    self._shape = check_shape(M.shape)

                self.row, self.col = M.nonzero()
                self.data = M[self.row, self.col]
                self.has_canonical_format = True

        if dtype is not None:
            self.data = self.data.astype(dtype, copy=False)

        self._check()