addIntendedFor.py

import json
import os
import subprocess
import sys

bidsdir = sys.argv[1]


files = os.listdir(bidsdir)
subs=[x for x in files if x.startswith('sub')]

for subj in subs:

    #makes list of the json files to edit
    files=[os.path.join('%s/%s/fmap'%(bidsdir,subj), f) for f in os.listdir('%s/%s/fmap'%(bidsdir,subj))]
    files_json = [i for i in files if i.endswith('.json')]
    #makes list of the func files to add into the intended for field
    files = ["func/%s"%(file) for file in os.listdir('%s/%s/func'%(bidsdir,subj))]
    files_txt = [i for i in files if i.endswith('.nii.gz')]

    #This could be done better but we open the json files ('r' for read only) as a dictionary add the Intended for key 
    #and add the func files to the key value
    #The f.close is a duplication. f can only be used inside the with "loop"# we open the file again to write only and dump the dictionary to the files
    for i in range(len(files_json)):
        with open(files_json[i],'r')as f:
            data=json.load(f)
            data["IntendedFor"]=files_txt
            f.close
        with open(files_json[i],'w')as f:
            json.dump(data,f,indent=4,sort_keys=True)
            f.close