Python script for Bitcoin addresses bulk balance checking.

pybitbalance.py

import argparse
import urllib3
from urllib3 import util
import json
import math

LIMIT = 120
SATOSHI = 1e+8


def check_balance(fi, fo):
    print('loading addresses...')
    f1 = open(fi)
    f2 = open(fo, 'w')
    addresses = []
    for l in f1:
        addresses.append(l.strip())
    print('addresses loaded:', len(addresses))
    print('getting balances info...')
    f1.close()
    http = urllib3.PoolManager(timeout=util.Timeout(10))
    total = len(addresses)
    steps = math.floor(total / LIMIT)
    remind = total % LIMIT
    for step in range(steps + 1):
        url = 'https://blockchain.info/balance?active='
        if step < steps:
            for a in range(LIMIT):
                url += addresses[a] + '|'
        else:
            for a in range(remind):
                url += addresses[a] + '|'
        url = url[:-1]
        res = http.request('GET', url, timeout=util.Timeout(10), retries=util.Retry(10))
        data = json.loads(res.data.decode('utf-8'))
        for address in data:
            balance = data[address]['final_balance'] / SATOSHI
            n_tx = data[address]['n_tx']
            b = '{0:.8f} '.format(balance)
            f2.write(address + '\t\t\t' + b + '\t\t\t' + str(n_tx) + '\n')
        print("%.2f" % ((step / (steps if steps > 0 else 1)) * 100), '%')
    f2.close()
    print('complete')


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument("fi", help="text file containing one address per line")
    parser.add_argument("fo", help="text file to save addresses with balance details")
    args = parser.parse_args()
    fi = args.fi
    fo = args.fo
    check_balance(fi, fo)

This is a great tool. How can I use it to check 6000 bitcoin addresses? It will only check 120 addresses and when I increase the limit to 6000 it throws an error.