Three or more variables with similar conditions, can they clash?

I'm not sure If I can post a follow up question with this thread - I just had one more question.

with the above condition, I added one more variable with identical constraints. After adding this third constraint, I receive the bottom message, am I not allowed to insert a third or fourth variable with similar constraints?

Prl = model.addVars(T,R, name = 'irrigation')

R = 4

#irrigation 
p_r_min = 0.85
p_r_max = 0.88
p_r_ttl = 4.4

#each irrigation motor cannot exceed or fall behind the min max 
model.addConstrs(Prl[t1,r] <= p_r_min for t1 in range(T) for r in range (R))
model.addConstrs(Prl[t1,r] >= p_r_max for t1 in range(T) for r in range (R)
if hoursof_ir[t1]!= 0)

KeyError: 0During handling of the above exception, another exception occurred:KeyError                                  Traceback (most recent call last)<ipython-input-3-33f692cd7f9e> in <module>    121 #each irrigation motor cannot exceed or fall behind the min max    122 model.addConstrs(Prl[t1,r] <= p_r_min for t1 in range(T) for r in range (R))--> 123 model.addConstrs(Prl[t1,r] >= p_r_max for t1 in range(T) for r in range (R)    124                 if hoursof_ir[t1]!= 0)    125 src/gurobipy/model.pxi in gurobipy.Model.addConstrs()<ipython-input-3-33f692cd7f9e> in <genexpr>(.0)    122 model.addConstrs(Prl[t1,r] <= p_r_min for t1 in range(T) for r in range (R))    123 model.addConstrs(Prl[t1,r] >= p_r_max for t1 in range(T) for r in range (R)--> 124                 if hoursof_ir[t1]!= 0)    125     126 #supplemental lighting constraint multiplying with time so that it operates during 0500-2300~/Documents/Programming_with_Python/anaconda3/lib/python3.8/site-packages/pandas/core/frame.py in __getitem__(self, key)   2798             if self.columns.nlevels > 1:   2799                 return self._getitem_multilevel(key)-> 2800             indexer = self.columns.get_loc(key)   2801             if is_integer(indexer):   2802                 indexer = [indexer]~/Documents/Programming_with_Python/anaconda3/lib/python3.8/site-packages/pandas/core/indexes/base.py in get_loc(self, key, method, tolerance)   2646                 return self._engine.get_loc(key)   2647             except KeyError:-> 2648                 return self._engine.get_loc(self._maybe_cast_indexer(key))   2649         indexer = self.get_indexer([key], method=method, tolerance=tolerance)   2650         if indexer.ndim > 1 or indexer.size > 1:

Official comment

Simranjit Kaur

Gurobi Staff

June 23, 2025 02:45 Edited

This post is more than three years old. Some information may not be up to date. For current information, please check the Gurobi Documentation or Knowledge Base. If you need more help, please create a new post in the community forum. Or why not try our AI Gurobot?.

Jaromił Najman

October 21, 2021 11:11

This is a continuation of this post.

October 21, 2021 12:06

Hi Olivia,

You can provide a full jupyter notebook file as described in Posting to the Community Forum. This would definitely make providing help easier.

Best regards,
Jaromił

Olivia Park

October 21, 2021 12:23

Thank you - will do !

October 21, 2021 13:59

The issue was that one pandas dataframe was not converted to list. This is resolved now.

Three or more variables with similar conditions, can they clash?

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