Python Forum

Hello Python community,
I am relatively new the language, and have most of my experience in MATLAB.
I've tried to already search for the answer to my question, however unsuccessfully. Perhaps I am missing the key words...

In any case, I am sure someone could help me rather easily, as I currently feel so:

I have a loop where I set the desired variables first:

feature_ics = {'All': features_all,
            'Brain': features_brain,
            'Artifact': features_artifact}

class_acc_mean = {'All': [], 'Brain': [], 'Artifact': []}
class_acc_std = {'All': [], 'Brain': [], 'Artifact': []}

Then, at the end of my code, I try to get all of the data I want [the data from 5 iterations of different variables 'j']

            logreg_acc_mean[sub_idx] = acc_test_mean
            logreg_acc_std[sub_idx] = acc_test_std
            #print("    Accuracy Subject %i: %.2f %%" %(sub_idx, acc_test_mean*100))


        # Add results to dictionary
        print(logreg_acc_mean)
        print(name)
        print(j)
        class_acc_mean[name,j]= logreg_acc_mean
        class_acc_std[name,j] = logreg_acc_std

An example output looks like this (Exactly what I want to save!):

Output:
------------------------------------------------------------------
Classification Features All
------------------------------------------------------------------
[0.46107143 0.26333333 0.74691176 0.64466667 0.50747253 0.47942857
 0.612      0.74142857 0.34580952 0.58695238 0.281      0.46009524
 0.29142857]
All
0
------------------------------------------------------------------
[0.45535714 0.22166667 0.59544118 0.60733333 0.32538462 0.50314286
 0.48980952 0.64371429 0.40704762 0.60057143 0.183      0.31057143
 0.24857143]
All
1
------------------------------------------------------------------
[0.25535714 0.29166667 0.37654412 0.48761905 0.30659341 0.35609524
 0.28895238 0.45428571 0.31371429 0.35257143 0.18       0.20666667
 0.31428571]
All
2
------------------------------------------------------------------
[0.34464286 0.19666667 0.47654412 0.49152381 0.32098901 0.5107619
 0.39695238 0.35152381 0.44238095 0.37857143 0.424      0.3787619
 0.39428571]
All
3
------------------------------------------------------------------
[0.47178571 0.225      0.49176471 0.46619048 0.43989011 0.514
 0.53657143 0.35304762 0.45904762 0.40542857 0.346      0.3347619
 0.33142857]
All
4
.
.
.

Yet, when I then call my variable 'class_acc_mean', I get:

Output:
.
.
.
 ('All',
  0): array([0.47285714, 0.21166667, 0.50441176, 0.45733333, 0.44494505,
        0.52638095, 0.51742857, 0.37219048, 0.45666667, 0.40466667,
        0.362     , 0.31085714, 0.32571429]),
 ('All',
  1): array([0.47285714, 0.21166667, 0.50441176, 0.45733333, 0.44494505,
        0.52638095, 0.51742857, 0.37219048, 0.45666667, 0.40466667,
        0.362     , 0.31085714, 0.32571429]),
 ('All',
  2): array([0.47285714, 0.21166667, 0.50441176, 0.45733333, 0.44494505,
        0.52638095, 0.51742857, 0.37219048, 0.45666667, 0.40466667,
        0.362     , 0.31085714, 0.32571429]),
 ('All',
  3): array([0.47285714, 0.21166667, 0.50441176, 0.45733333, 0.44494505,
        0.52638095, 0.51742857, 0.37219048, 0.45666667, 0.40466667,
        0.362     , 0.31085714, 0.32571429]),
 ('All',
  4): array([0.47285714, 0.21166667, 0.50441176, 0.45733333, 0.44494505,
        0.52638095, 0.51742857, 0.37219048, 0.45666667, 0.40466667,
        0.362     , 0.31085714, 0.32571429]),
.
.
.

Why does 'j' seem to update in my code, but then not save in the variable? How can I save the relevant data for each loop, as in the output during the code run itself? This is seemingly so simple but it's been driving me a bit mad.

Thank you!

You don't show, but I guess that your loop is for j in...?

Perhaps it would be easier for yourself to keep track of things by using the [inline]dictionary.update()[/inline] method rather than "="?  

[python]
your_dictionary.update({ new_key : new_value})

Hi Michael,

Thanks for the reply.

I suppose what I am trying to figure out is actually just this simple question:
1. I have three larger conditions [all, brain, artifact]. I want to create a variable to save classification accuracies for each of these.
2. I have five frequency bands "j" in which I've preprocessed my data [0,1,2,3,4].
3. I also have many subjects [n...nx].
4. I want to loop through the subjects for each band, for each condition and basically save a variable at the end which gives me back [conditions x freq][subjects]. At the moment, I have no problem when using a single freq band to get [conditions][subjects], but I can't figure out how to inlay the frequency bands to expand the variable in Python. This must of course be easy! I'm just a bit rusty

Hi,

Well first of all it would be nice, if you could share the logic where you loop over your dictionarys/arrays.

Hard to figure out what the problem is w/o the actual code.