Question

I’m working with a script that fits a line to a data set and outputs some fit parameters. The command that runs the fitter looks like:

fitter = Fitter(hdf2.root.OM01, plot=False).

I’d like to loop this command so that it outputs the fit parameters for the files 'hdf2.01', 'hdf2.02', ... 'hdf2.50'

How can I loop this code?

Answer 1

If I understand correctly, you have an object that has numbered properties (OM01 through OM50). You can generate these attribute names with a loop, and use getattr to retrieve them from the object.

If your object is called root, as it is in your comment, you could do the following:

parameters = []
for i in range(1, 51):
    parameter = getattr(root, 'OM%02d' % i)
    parameters.append(parameter)

# now all of your parameters are in the parameter array

or, if you like list comprehensions (and who doesn’t):

parameters = [getattr(root, 'OM%02d' % i) for i in range(1, 51)]

I guess you need to use these parameters with Fitter, which you could do as follows:

results = []
for i in range(1, 51):
    parameter = getattr(hdf2.root, 'OM%02d' % i)
    result = Fitter(parameter, plot=False)
    results.append(result)

EDIT: If your files just have the names “hdf2.root.OM01”, “hdf2.root.OM02”, etc. you can just do this:

results = []
for i in range(1, 51):
    filename = 'hdf2.root.OM%02d' % i
    result = Fitter(filename, plot=False)
    results.append(result)