shell.txt
a1 b1 0.2 0
a1 c1 0.8 0
b1 c1 0.7 0
a2 b2 1 0
a2 d2 0.4 0
d2 b2 0.6 0
a1 a2 1 1
a2 a1 0.1 1
b1 b2 0.5 1
b2 b1 0 1

with open('shell.txt') as f: lines = f.readlines() mylist = [line.strip().split() for line in lines]

Since the txt data is all string type after loading, now we need to convert the last two columns into integer types. Please give me some clean methods, thank you