# What is the best way to get a large number of RNA seq data from SRA in Python without being denied access

I have the following code to download data from the SRA using multithreading in Python. After running this a few times now (for testing purposes), I keep getting denied access to the data. Not sure how to fix this. In particular, cating the output files gives:

<?xml version="1.0" encoding="UTF-8"?><Error><Code>AccessDenied</Code><Message>Access Denied</Message><RequestId>cb0f0e98-cafb-1dd7-9b7b-d8c49756ec52</RequestId><HostId>QeDGVwBXYp61J0B4_OUTn7UsEsiQEec0n18DAeR0kaE</HostId></Error>


Here is my code:

import threading
import requests
import time

start = time.perf_counter()

def __init__(self, url):
self.url = url
self.result = None
self.filename = url.split('/')[-1]
def run(self):
res = requests.get(self.url)
with open(self.filename, 'wb') as f:
f.write(res.content)
urls = [