创建带有值的字典项目列表

Question

i am working on program to create a dictionary of list of items values here is code

list_4 = ['A&A OMSS 10.1.2.0/24 10.1.1.0/24 Authorisation_Response', 'A&A OMSS 10.1.2.0/24 10.1.1.0/24 Authentication_Response', 'OMSS A&A 10.1.1.0/24 10.1.2.0/24 Authorsiation_Request', 'OMSS A&A 10.1.1.0/24 10.1.2.0/24 Authentication_Request', 'A&A AFM 10.1.2.0/24 10.1.3.0/24 Authorisation_Response', 'AFM A&A 10.1.3.0/24 10.1.2.0/24 Priviliged_Authentication_Request', 'A&A AFM 10.1.2.0/24 10.1.3.0/24 Privilged_Authentication_Response', 'AFM A&A 10.1.3.0/24 10.1.2.0/24 Priviliged_Authorisation_Request', 'A&A AFM 10.1.2.0/24 10.1.3.0/24 Authorisation_Response']
dict_1 = {'OMSS': '10.1.1.0/24', 'A&A': '10.1.2.0/24', 'AFM': '10.1.3.0/24', 'ATM': '10.1.4.0/24'}

for key, value in dict_1.items():
    for i in list_4:
        src_sys, dst_sys, src, dst, fun = i.split()
        if src_sys.strip() == key.strip():
            dict_2[key] = (src+" "+dst+" "+fun)

i am getting the below output

{'A&A': '10.1.2.0/24 10.1.1.0/24 Authorisation_Response', 'AFM': '10.1.3.0/24 10.1.2.0/24 Priviliged_Authorisation_Request', 'OMSS': '10.1.1.0/24 10.1.2.0/24 Authorsiation_Request'} 

but i want the below output

{'A&A': [list of flows that start with A&A], 'AFM': [list of flows that start with AFM]', 'OMSS': [list of flows that start with OMSS]} 

Answer 1

The reason is that you are overwriting the value for the specific key iteratively instead of appending them to a list as you require.

collections.defaultdict is made specifically for this purpose. Read more about it here . Check this code -

from collections import defaultdict
dict_2 = defaultdict(list)  #dictionary where each value is an empty list by default

for key, value in dict_1.items():
    for i in list_4:
        src_sys, dst_sys, src, dst, fun = i.split()
        if src_sys.strip() == key.strip():
            dict_2[key].append(src+" "+dst+" "+fun) #<---- append to the key's value
            
dict_2 = dict(dict_2)

{'OMSS': ['10.1.1.0/24 10.1.2.0/24 Authorsiation_Request',
          '10.1.1.0/24 10.1.2.0/24 Authentication_Request'],
 'A&A': ['10.1.2.0/24 10.1.1.0/24 Authorisation_Response',
         '10.1.2.0/24 10.1.1.0/24 Authentication_Response',
         '10.1.2.0/24 10.1.3.0/24 Authorisation_Response',
         '10.1.2.0/24 10.1.3.0/24 Privilged_Authentication_Response',
         '10.1.2.0/24 10.1.3.0/24 Authorisation_Response'],
 'AFM': ['10.1.3.0/24 10.1.2.0/24 Priviliged_Authentication_Request',
         '10.1.3.0/24 10.1.2.0/24 Priviliged_Authorisation_Request']}