How to operate with lines received from a file?

Question

Python

There is a file where some numbers are written on each line. We need to read these numbers and, let's say, multiply each of them by 2. Can you give an example code? Why is mine not working?

a = open('sometext.txt', 'r')
b = []
b = a.readlines()
for line in a.readlines():
  line = int(line) * 2
  b.append(line)

Answer 1

Padawans get used to clearing strings from dark characters like '\n'
or
or
By the way, as a debugger, a simple print or pprint.pprint() helps a lot
here too

b = a.readlines()
for line in a.readlines():

extra something, for example list b

Answer 2

ejiffjwei 2
qehfiuefw 4

with open("sometext.txt") as f:
    data = f.readlines()
    print [int(filter(str.isdigit, st))*2 for st in data]

output: [4,8]