logreg.py

with pm.Model() as m:
    pi = data.partner_id.astype('category').cat.codes.values
    ii = data.item_id.astype('category').cat.codes.values
  
    # [rest of priors here]
    item_sigma = pm.Exponential('item_sigma', 1)
    b_item = pm.Normal('b_item', 0, item_sigma, shape=ii.nunique())
  
    p = pm.math.invlogit(
        a
        + ..
        + b_item[ii]
    )
    
    pm.Binomial('obs', p=p, n=data.observations.values, observed=data.successes.values)