使用 f.readline() 读取特定行 - Discord.py

Question

async def token():
  global counterA
  global counterB
  
  counterA = 0
  counterB = 0
  
  
  while True:
    await asyncio.sleep(5)
    counterA += 1
    counterB += 2
    
    with open('counter.txt', 'w') as f:
        f.write (str(counterA))
        f.write ("\n")
        f.write (str(counterB))
        f.write ("\n")

@client.event
async def on_ready():
    global counterA
    global counterB

    with open('counter.txt', 'r') as f:
      counterA = int(f.readline())
    with open('counter.txt', 'r') as f:
      counterB = int(f.readline())

    print('Logged in as')
    print(client.user.name)
    print(client.user.id)
    print('------')

client.loop.create_task(token())
client.run(TOKEN)

Im trying to read the second line (counterB) when I turned the bot on, so the counter doesn't restart

Instead of getting the second line (counterB) value, I got the first line value(counterA) when i run the bot

So, Im trying to get a specific / certain line from counter.txt

Answer 1

readline() reads a file line by line.

If you need a random line info from a file, you can use the readlines() method which returns the lines as a list and then you can use the index based access to directly get a particular line info.

For example, to get second line value, use the following:

with open('counter.txt', 'r') as f:
      lines = f.readlines()
      secondLine = lines[1]

Answer 2

f.readlines() returns a list of lines, eg my txt file looks like this:

Hello world!
This is something
I'm writing

The return result of f.readlines would be:

result = ["Hello World!\n", "This is something\n", "I'm writing\n"]

Let's say I want the second line:

>>> line = 2
>>> result[line - 1] # Remember, indexes start at 0
"This is something\n"

Answer 3

If you want only one line,then instead of reading all lines,read untill you get N th line,

s=''
for i in range(n) :
  s=f.readline()