python生成随机二进制文件

import random
def genFile(filename,block=1,size=1):
        f=open(filename,"wb")
        content=""
        #for j in range(1024*1024):
        for j in range(1):
                content=bytes(b"")
                #for i in range(1024):
                for i in range(1):
                        c=chr(random.randint(0,255)).encode('utf-8')
                        content=content+c
                f.write(content)
 
print(len(sys.argv))
if len(sys.argv) != 2:
        print("usage:	"+sys.argv[0]+"	outfilename")
        sys.exit(1)
genFile(sys.argv[1],1024,1024*1024)