How to sort through a yaml file and provide values for each tree

Question

I am working on a script to read through a YAML config and am having some problems with the logic with the for loops and dictionary. I can get it to print each value when done static, but this throws off the purpose of my script. As I would like to dynamically call functions using the YAML config file.

So far I can only get the first key and value from my for script. Anytime I try to go further by using dataMap[key][0][value] I cannot go further then 1.

import yaml

with open('design.yaml') as f:
    dataMap = yaml.safe_load(f)
print("================================")
print("Topo #1")
print("================================")
print(f"Topo Name: {dataMap['topology'][0]['name']}")
print(f"vPort: {dataMap['topology'][0]['vport']}")
print(f"DG Name: {dataMap['topology'][1]['devicegroup']}")
print(f"Multiplier: {dataMap['topology'][1]['multiplier']}")
print(f"Eth Name: {dataMap['topology'][1]['eth']['name']}")
print("Auto Output - To look just like above")
print("================================")
for key, value in dataMap.items():
    #Updated
    print("KEY: {} - VALUE: {}".format(key, value[0].items()))
    print("====")
print("================================")
#print("Recursive Function Test")
#print("================================")
#myprint(dataMap)

config:
 -name: Test
topology:
 - name: DC1
   vport: Port1
 - devicegroup: DC1 DG1
   multiplier: 50
   eth:
     name: ETH1
     macStart: 00:01:01:01:00:01
     macStep: 00:00:00:00:00:01
     enableVLAN: True
     vlanID: 100
     vlanStep: 0
   ipv4:
     name: DC1 DG1 IPv4
     startIP: 10.1.1.10
     stepIP: 0.0.0.1
     netmask: 255.255.255.0
     gateway: 10.1.1.1
     gwStep: 0.0.0.0
 - name: TEST2
   vport: Port2
 - devicegroup: TEST DG2

Output:
KEY: config - VALUE: dict_items([('apiServer', '10.255.251.105'), ('apiServerPort', 443), ('osPlatform', 'linux'), ('username', 'admin'), ('password', 'admin'), ('chassisIP', '10.253.0.82'), ('licenseserver', '10.253.0.82'), ('licensemode', 'subscription'), ('licensetier', 'tier3'), ('POCName', 'XXXXX'), ('POCNumber', 'XXXXX')])
====
KEY: topology - VALUE: dict_items([('name', 'DC1'), ('vport', 'Port1')])

My problem is now, how do I pull in the devicegroup information from the YAML file? Changing value[0] to value[1] causes an index issue.

print("KEY: {} - VALUE: {}".format(key, value[1].items()))
IndexError: list index out of range

So how do I step further into the YAML file with this?

Answer 1

I am not 100% sure, but I don't think a function call within an f-string is evaluated, so try and do:

    print("KEY: {} - VALUE: {}".format(key, value[0].items()))

instead.

Additionally the value for the key config is a sequence (i.e. loaded as a Python list) that has only one element, so you cannot index further in that sequence then 0.

You'd better try and do something like:

for key, values in dataMap.items():
    for idx, value in enumerate(values):
        print("KEY: {} - VALUE[{}]: {}".format(key, idx, value.items()))
        print("====")