python使用subprocess执行linux命令

#等待返回，设置callback为True
import subprocess
def executeshell_by_call(command, callback=False):
    """
    执行shell命令
    必须加上close_fds=True，否则子进程会一直存在
    """
    if callback:
        obj = subprocess.Popen(command, shell=True, close_fds=True, stdout=subprocess.PIPE)
        lines = obj.stdout.readlines()
        if len(lines) == 1:
            lines = str(lines[0], encoding='utf-8').strip('\n')
        return lines
    else:
        return subprocess.Popen(command, shell=True)
command = 'wget -O /home/nvd_filesss/nvdcve-1.1-modified.json.zip  https://nvd.nist.gov/feeds/json/cve/1.1/nvdcve-1.1-modified.json.zip'
executeshell_by_call(command)
command = 'unzip  -o  /home/nvd_filesss/nvdcve-1.1-modified.json.zip'
executeshell_by_call(command)
file = open(f"/home/nvd_filesss/nvdcve-1.1-modified.json", encoding='utf-8')
print("-------------------------是否等待下载完成---------------------")