You can do: nums3 = [r.measure_value for r in db().select(db.Measures.measure_value)]
The .select() returns a Rows object, which acts like a list of Row objects -- if you want to extract just a single value from each Row object, you have to iterate through the Rows object and pull each value out. Note, depending on what you are doing, you can instead operate on the Rows object itself (rather than generating a list and then operating on the list). For example, to randomize the order: import random random_rows = db(db.Measures).select().sort(lambda r: random.random()) Anthony On Monday, May 26, 2014 6:20:07 AM UTC-4, Syd Stewart wrote: > > Hi > > What is the simplest way please to select a column of figures (floats and > int) into a list, so I can manipulate the list e.g randomise the order > > nums3 = db(db.Measures).select( db.Measures.measure_value, > orderby=db.Measures.measure_date_time) > > meannums= sum(nums3)/float(len(nums3)) > > This calculation of the mean keeps giving me an error > > File "/home/sydstewart/web2py/applications/SydOwn/controllers/test.py" > <https://sydstewart.pythonanywhere.com/admin/default/edit/SydOwn/controllers/test.py>, > line 92, in cusum > qnum[i][k] = (nums3[k]) - (meannums) > TypeError: unsupported operand type(s) for -: 'Row' and 'int' > > > Thanks > > > -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
