I am trying to create B-splines with the patsy package on a ipynb notebook on JupyterLab:
from patsy import dmatrix
bs = dmatrix("bs(x, df=50, degree=1) - 1", {"x": x})
axes[0].plot(x, bs)
axes[0].set_title("Basis functions")
plt.show()
This works fine the first time I run it. But when I try to rerun this cell again, it fails with the following error:
-----------------------------------------------------
TypeError Traceback (most recent call last)
/opt/conda/lib/python3.8/site-packages/patsy/compat.py in call_and_wrap_exc(msg, origin, f, *args, **kwargs)
35 try:
---> 36 return f(*args, **kwargs)
37 except Exception as e:
/opt/conda/lib/python3.8/site-packages/patsy/eval.py in eval(self, expr, source_name, inner_namespace)
164 code = compile(expr, source_name, "eval", self.flags, False)
--> 165 return eval(code, {}, VarLookupDict([inner_namespace]
166 + self._namespaces))
<string> in <module>
TypeError: 'DesignMatrix' object is not callable
The above exception was the direct cause of the following exception:
PatsyError Traceback (most recent call last)
<ipython-input-6-6ed4ba95a384> in <module>
2
3 _, axes = plt.subplots(2, figsize=(16, 16))
----> 4 bs = dmatrix("bs(x, df=50, degree=1) - 1", {"x": x})
5 axes[0].plot(x, bs)
6 axes[0].set_title("Basis functions")
/opt/conda/lib/python3.8/site-packages/patsy/highlevel.py in dmatrix(formula_like, data, eval_env, NA_action, return_type)
288 """
289 eval_env = EvalEnvironment.capture(eval_env, reference=1)
--> 290 (lhs, rhs) = _do_highlevel_design(formula_like, data, eval_env,
291 NA_action, return_type)
292 if lhs.shape[1] != 0:
/opt/conda/lib/python3.8/site-packages/patsy/highlevel.py in _do_highlevel_design(formula_like, data, eval_env, NA_action, return_type)
162 def data_iter_maker():
163 return iter([data])
--> 164 design_infos = _try_incr_builders(formula_like, data_iter_maker, eval_env,
165 NA_action)
166 if design_infos is not None:
/opt/conda/lib/python3.8/site-packages/patsy/highlevel.py in _try_incr_builders(formula_like, data_iter_maker, eval_env, NA_action)
64 if isinstance(formula_like, ModelDesc):
65 assert isinstance(eval_env, EvalEnvironment)
---> 66 return design_matrix_builders([formula_like.lhs_termlist,
67 formula_like.rhs_termlist],
68 data_iter_maker,
/opt/conda/lib/python3.8/site-packages/patsy/build.py in design_matrix_builders(termlists, data_iter_maker, eval_env, NA_action)
691 # on some data to find out what type of data they return.
692 (num_column_counts,
--> 693 cat_levels_contrasts) = _examine_factor_types(all_factors,
694 factor_states,
695 data_iter_maker,
/opt/conda/lib/python3.8/site-packages/patsy/build.py in _examine_factor_types(factors, factor_states, data_iter_maker, NA_action)
441 for data in data_iter_maker():
442 for factor in list(examine_needed):
--> 443 value = factor.eval(factor_states[factor], data)
444 if factor in cat_sniffers or guess_categorical(value):
445 if factor not in cat_sniffers:
/opt/conda/lib/python3.8/site-packages/patsy/eval.py in eval(self, memorize_state, data)
562
563 def eval(self, memorize_state, data):
--> 564 return self._eval(memorize_state["eval_code"],
565 memorize_state,
566 data)
/opt/conda/lib/python3.8/site-packages/patsy/eval.py in _eval(self, code, memorize_state, data)
545 def _eval(self, code, memorize_state, data):
546 inner_namespace = VarLookupDict([data, memorize_state["transforms"]])
--> 547 return call_and_wrap_exc("Error evaluating factor",
548 self,
549 memorize_state["eval_env"].eval,
/opt/conda/lib/python3.8/site-packages/patsy/compat.py in call_and_wrap_exc(msg, origin, f, *args, **kwargs)
41 origin)
42 # Use 'exec' to hide this syntax from the Python 2 parser:
---> 43 exec("raise new_exc from e")
44 else:
45 # In python 2, we just let the original exception escape -- better
/opt/conda/lib/python3.8/site-packages/patsy/compat.py in <module>
PatsyError: Error evaluating factor: TypeError: 'DesignMatrix' object is not callable
bs(x, df=50, degree=1) - 1
^^^^^^^^^^^^^^^^^^^^^^
Ends up it was because of myself overriding the variable bs hence overriding the bs function inside the patsy string.
This is why eval is an antipattern as usual...