将文件导入到json密钥中

def import_proxies():
    global proxies_json
    proxies_json = {'http': {}}
    with open("proxies.txt", 'r', encoding='utf8') as proxy_file:
        for line in proxy_file:
            val = line.split()
            proxies_json[['http'][val]] = val
            print(proxies_json)


import_proxies()

My erorr: TypeError: list indices must be integers or slices, not list