如何从这个 for 循环代码中创建一个列表？

Question

This should not be too hard, I just really cannot figure it out. I have this set of code:

file_open=open('mbox-short.txt','r')
counter=0
for line in file_open:
    if line.startswith('From:') and line.find('localhost')==-1:
        counter+=1
        line.strip()[6:]
file_open.close()

I am wondering how I can save the results of this loop in a list. Thank you!

Answer 1

.append() to append eleman to list

file_open=open('mbox-short.txt','r')
list = []
counter=0
for line in file_open:
    if line.startswith('From:') and line.find('localhost')==-1:
        counter+=1
        list.append(line.strip()[6:])
file_open.close()

https://docs.python.org/3/c-api/list.html

Answer 2

You could read all the lines in and then use a simple list comprehension.

with open('mbox-short.txt','r') as file_open:
  lines = file_open.readlines()
  lst = [line.strip()[6:] for line in lines if line.startswith('From:') and line.find('localhost')==-1]

print(lst)