Python in ArcGIS - Lookup values in a dictionary and print corresponding value into a new field -

i new python , have been trying days work write function decodes field in attribute table , adds corresponding value (from dictionary below) blank field. (similar vlookup in excel). example when 'e1' shows in attribute table 'e' in dictionary, find corresponding value in dictionary , print list , '1' , print same list (blank field has been added attribute table). add list blank field in attribute table.

your data structure not friend @ point.

you have information stacked in nested dictionary structure, better off decoding first:

#!python3  import collections import itertools  luc_dict = {    'estu':'estuaries',    'ice':'ice',    'lake':'lake',    'quar':'quarries/mines',    'rive':'river',    'town':'town/urban',    'class':{'1':'arable (1)',        '2':'arable (2)',        '3':'arable (3)',        '4':'arable (4)',        '5':'non arable (5)',        '6':'non arable (6)',        '7':'non arable (7)',        '8':'protected (8)'},    'subclass':{'c':'climiate',        'e': 'erosion',        's': 'soil',        'w': 'wetness'}}  field1_value = {k:v k,v in luc_dict.items() if k not in ('class','subclass')} field2_value = collections.defaultdict(str)  classes = luc_dict['class'] subclasses = luc_dict['subclass']  c,sc in itertools.product(classes.keys(), subclasses.keys()):     field1_value[c+sc] = classes[c]     field2_value[c+sc] = subclasses[sc]   def decode(instr):     return field1_value[instr], field2_value[instr]  tests = "6e 4s rive 2s estu"  test in tests.split():     f1, f2 = decode(test)     print("{}: [{}, {}]".format(test, f1, f2)) 

the output looks like:

6e: [non arable (6), erosion] 4s: [arable (4), soil] rive: [river, ] 2s: [arable (2), soil] estu: [estuaries, ] 

which think have in mind.