Extract number from the string

Split the string at n characters. Then for every line, split it at : and append the number to a list:

string = "Tesla Model 3 LR 4WD:560nTesla Model Y LR 2WD:540"

lines = string.split("n")
nums = []

for line in lines:
    nums.append(int(line.split(":")[-1]))

I assume that you get data as string. Also, you need value after the colon.

Then you can use split function from string.

data = "Tesla Model 3 LR 4WD:560"
value = data.split(":")[-1]

If you can use a regex:

string = 'Tesla Model 3 LR 4WD:560nTesla Model Y LR 2WD:540'

import re

out = re.findall('(?<=:)d+', string)

Output: ['560', '540']

If you want integers:

out = [int(x.group()) for x in re.finditer('(?<=:)d+', string)]

Output: [560, 540]

This snippet should read strings from file, and extract the numbers from the strings into a list.

def findNumber(text):
    # Returns the number after the colon as integer.
    return int(text.split(':')[-1])

# Open the file containing the lines/strings
with open('file.txt') as file:
    lines = file.readlines()

# extract the number fr
data = list(map(findNumber, lines))

print(data)

You can also use list comprehension:

text = 'Tesla Model 3 LR 4WD:560nTesla Model Y LR 2WD:540'
num = [int(n) for i in text.split('n') for n in i.split(':') if n.isdigit()]
print(num)

# [560, 540]