如何在永远循环中运行函数？

Question

i want to loop forever my function. but i'm having a struggle.

import os
import requests
import glob
import time 
import base64

url = 'http://0.0.0.0:5000/'

def load_data():

    os.chdir('./40_mb')
    for image in glob.glob('*.jpg'):
        with open(image, 'rb') as imageFile:
            # image_s = base64.b64encode(imageFile.read())
            image_s = {'file_image':open(image, 'rb')}

    return image_s

def send_data():


    start = time.time()
    r = requests.post(url, files = load_data())
    end = time.time()

    print('client 1: {} ms'.format((end - start)*1000))



if __name__ == "__main__":
    while True:
        send_data()

when i run it, i get this error:

Traceback (most recent call last):
  File "http_1.py", line 32, in <module>
    send_data()
  File "http_1.py", line 23, in send_data
    r = requests.post(url, files = load_data())
  File "http_1.py", line 11, in load_data
    os.chdir('./40_mb')
FileNotFoundError: [Errno 2] No such file or directory: './40_mb'

without while True my code runs fine. does anyone can help my problem? sorry if this a silly question. thanks in advance

Answer 1

Its seems you are not redirecting to the correct directory when in the while loop. Essentially to fix this you will want to is change your working directory to where you originally started from. A really clean and convenient way to do that would be to use it in a context manager, just for a cleaner more reusable code.

import os
import os
import requests
import glob
import time 
import base64
from contextlib import contextmanager


@contextmanger
def workingdir(path):
    try:
       origin = os.getcwd()
       os.chdir(path)
       yield
    except:
       print('error occured') #might be better to logging the error instead of a just a print statement
    finally:
        os.chdir(origin)

url = 'http://0.0.0.0:5000/'

def load_data():

    with workingdir(path):
        for image in glob.glob('*.jpg'):
            with open(image, 'rb') as imageFile:
                # image_s = base64.b64encode(imageFile.read())
                image_s = {'file_image':open(image, 'rb')}

        return image_s

def send_data():


    start = time.time()
    r = requests.post(url, files = load_data())
    end = time.time()

    print('client 1: {} ms'.format((end - start)*1000))



if __name__ == "__main__":
    while True:
        send_data()

With this every time the while loop runs, it comes right back the directory it started from.