如何在Python中访问文件（.txt）中的下一行

Question

I have a file and I open it and then I check for few things. If the line starts with "E PARAM" and also has "OOPS1" in it somewhere then I want to check that the next line starts with " E PARAM". If not I will make a new file and copy it there till the time I dont hit another "E PARAM" line. Since Python doesnt have a next() option... what can help me here

import string
import os


A = "k_trap_cur"
B = open(A, 'r+')
lines = B.readline()

for lines in B:
    if lines.startswith("E PRAM"):
        if "OOPS: 1" in lines:
            while lines.next().startswith("E PARAM") == False: // HERE I want to access next line
                print " YES"

Answer 1

If I understood you right:

b = open(a, 'r+')
for line in b:
    if line.startswith("E PRAM") and "OOPS: 1" in line:
        next_line = next(b)
        # do whatever you need

Files provide what is called an “Iterator protocol” and that's why they work in for -loops. You can also call next function on them manually, if you want. Check PEP-234 for more details.