[Python] YAML implementation in Python help, 2 weeks beginner

I made this Python script so its faster to edit Netplan YAML files, but for some reason it gives more errors than enything, and it doesn't netplan apply for some reason, please explain as much as you want I want to learn from this. I am using Ubuntu 24.04, and python3. thanks in advance!. I dont know what to write more but its asking me to write more details so.... I like dogs.... 2+2 is 4.... num1 = input("introduce a number:") num2= input("introduce a secund number") print(f{num1} + {num2} = {num1+num2})

import os
import subprocess
import yaml

#Welcoming banner
print("---------- NETPLANCHANGER ----------")
netplan_folder = "/etc/netplan"

def CheckIfRoot():
#Verifies root perms
if os.getuid() != 0:
print("You need to run this script as root")
exit(1)

def SelectYAML(netplandir):
#List of options
netplanoptions = [f for f in os.listdir(netplandir) if f.endswith(('.yaml', '.yml'))]
print(netplanoptions)
while True:
SELECT_NETPLAN = input("What file do you want to edit?: ")
if SELECT_NETPLAN in netplanoptions:
return SELECT_NETPLAN
else:
print("File not valid.\n")



def ContentNBackup(netplandir, SELECT_NETPLAN):
try:
#Paths
absolutepath = os.path.join(netplandir, SELECT_NETPLAN)
absolutebackup = absolutepath + ".bak"

#Open .yaml/.yml
with open(absolutepath, 'r') as file:
print("\nFile content:")
print("----------------------------------")
print(file.read())

with open(absolutebackup, 'w') as file:
netplanabierto = open(absolutepath, 'r').read()
file.write(netplanabierto)
print("----------------------------------")
print(f"Backup of {SELECT_NETPLAN} in {absolutebackup}")
return absolutepath

except FileNotFoundError:
print("File not found")


def OpenYAML(absolutepath):
#Open YAML file and loads it
with open(absolutepath, 'r') as file:
Data = yaml.safe_load(file)
return Data


def SelectIF(yamldata):
#Interface selection
try:
print("\n")
result = subprocess.run(['ip', '-o', 'link', 'show'], capture_output=True, text=True)
interfaces = []
for line in result.stdout.splitlines():
iface = line.split(': ')[1].split('@')[0]
if iface != "lo":
interfaces.append(iface)
print(iface)

while True:
Interface = input("Select the interface you want to edit: ")
if Interface not in interfaces:
print("Select a valid interface")
continue
else:
break
except Exception as e:
print(f"Error selecting the interface {e}")
exit(1)

return Interface


def NetplanNewEntries(yamldata, interface):
#Creates new entries in YAML file
dhcp = input("Do you want to use DHCP (y/n)?: ").lower()
while dhcp not in ['y', 'n']:
print("Please enter 'y' or 'n'.")
dhcp = input("Do you want to use DHCP (y/n)?: ").lower()

if 'network' not in yamldata:
yamldata['network'] = {}

if 'ethernets' not in yamldata['network']:
yamldata['network']['ethernets'] = {}

if interface not in yamldata['network']['ethernets']:
yamldata['network']['ethernets'][interface] = {}

if dhcp == "n":
yamldata['network']['ethernets'][interface]['dhcp4'] = False
if 'addresses' not in yamldata['network']['ethernets'][interface]:
yamldata['network']['ethernets'][interface]['addresses'] = []
if 'nameservers' not in yamldata['network']['ethernets'][interface]:
yamldata['network']['ethernets'][interface]['nameservers'] = {"addresses": []}
if 'gateway4' not in yamldata['network']['ethernets'][interface]:
yamldata['network']['ethernets'][interface]['gateway4'] = ""
else: # dhcp == "y"
yamldata['network']['ethernets'][interface]['dhcp4'] = True

return dhcp



def UserConfig():
#User inputs for config
ip = input("New IP Address in CIDR formar (ej 192.168.1.10/24): ")
gateway = input("Gateway (ej: 192.168.1.1): ")
dns_raw = input("DNS separated by comma (ej: 8.8.8.8,4.4.4.4)")
dns = [d.strip() for d in dns_raw.split(",")]
return ip, gateway, dns


def NetplanMod(interface, dhcp, ip, gateway, dns, yamldata):
#Modifying YAML
if dhcp == "y":
return

if dhcp == "n":
yamldata['network']['ethernets'][interface]['addresses'] = [ip]
yamldata['network']['ethernets'][interface]['gateway4'] = gateway
yamldata['network']['ethernets'][interface]['nameservers'] = {"addresses": dns}
return

def SaveYAML(yamlpath, yamldata):
#Saving YAML
print("New YAML content:\n")
print("-------------------")
print(yaml.dump(yamldata, default_flow_style=False))
with open(yamlpath, 'w') as file:
yaml.dump(yamldata, file, default_flow_style=False)
print(f"Netplan saved to {yamlpath}.")

def ApplyNetplan():
#Aplies netplan
try:
result = subprocess.run(['netplan', 'apply'], check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
print("Netplan applied successfully.")
except subprocess.CalledProcessError as e:
print("Error applying Netplan: ")
print(e.stderr.decode())


def Main():
#Main function
CheckIfRoot()

selectednetplan = SelectYAML(netplan_folder)

YAMLAbsolutePath = ContentNBackup(netplan_folder, selectednetplan)

YAMLData = OpenYAML(YAMLAbsolutePath)

UserInterface = SelectIF(YAMLData)

UserDHCP = NetplanNewEntries(YAMLData, UserInterface)

if UserDHCP == "n":
UserIP, UserGateway, UserDNS = UserConfig()
NetplanMod(UserInterface, UserDHCP, UserIP, UserGateway, UserDNS, YAMLData)

else:
print("DHCP selected, skipping IP/Gateway/DNS input.")

SaveYAML(YAMLAbsolutePath, YAMLData)

ApplyNetplan()

return

Main()

Continue reading...