Originally posted by: ShaCplex

 Hi sir,

I have been working in OPL and Java API and now trying to switch to python cplex.

I have a dataframe named odRoutes which has many columns (head() of the dataframe is attached).

I want to create a continuous variable for each of the rows in the dataframe OdRoutes, so I wrote;

mdl = Model("LP")

varODRoute = mdl.continuous_var_dict(valid_ODRoutes_df,name="var_route")

by doing this I am getting the variable names as var_route_0 , var_route_1, etc

the odRoutes dataframe has columns named 'name','productCategory' etc. I want to create variables and name it as var_route_{name+productCategory} for each of the variable.

How can I achieve this? can you please assist me.

regards,

shahul

Did you see this part of the help text for Model.continuous_var_dict:

 |          name: Used to name variables. Accepts either a string or
 |              a function. If given a string, the variable name is formed by appending the string
 |              to the string representation of the key object (if `keys` is a sequence) or the
 |              index of the variable within the range, if an integer argument is passed.
 |              If passed a function, this function is called on each key object to generate a name.
 |              The default behavior is to call :func:`str` on each key object.
 |      
 |          key_format: A format string or None. This format string describes how `keys` contribute to variable names.
 |                      The default is "_%s". For example if name is "x" and each key object is represented by a string
 |                      like "k1", "k2", ... then variables will be named "x_k1", "x_k2",...

So you can either pass a function to name in order to create the name or try to use the key_format argument with an appropriate format string.

Originally posted by: ShaCplex

Hi Daniel,

Thanks for the suport.

seems like , the assignment,

mdl.continuous_var_dict(keys=valid_ODRoutes_df,name=lambda odr:"var_route_%s" % (odr.loc['OD Route']))  is also not working. 

how to make this happen?

valid_ODRoutes_df is a dataframe

Thanks,

Shahul

odr in your case is the row label. So this should work:

from docplex.mp.model import Model
import pandas as pd

df = pd.DataFrame({'OD Route' : ['Route1', 'Route2', 'Route3'],
                   'name'     : ['Name1',  'Name2',  'Name3'  ]})
print(df)
with Model() as model:
    x = model.continuous_var_dict(keys=df,
                                  name=lambda odr:"var_route_%s_%s" % (df['OD Route'][odr], df['name'][odr]))
    print(x)