primitive version of my proprietary 3d format

from sys import argv
from struct import pack
from math import ceil,log
if len(argv) < 2: print("no file name given!"); exit()
vertices,faces=[],[]; byteBuff=b''; lineNum=1; amountMax=0
fileI=open(argv[1],"r")
for l in fileI:
    line=l[:-1].split(" ")
    if line[0] == "v":
        byteBuff=b''
        for v in range(1,len(line)): byteBuff+=pack("f", float(line[v]))
        vertices.append(byteBuff)
    elif line[0] == "f":
        faces.append([]); last=len(faces)-1
        for index in range(1,len(line)): faces[last].append( int(line[index].split("/")[0])-1 )
        if len(faces[last]) != 3: print(("line {}: face is not a triangle").format(lineNum)); exit()
    lineNum+=1
fileI.close(); fileO=open(argv[1].split(".")[0]+".rtr","wb")
for face in faces: amountMax=max(amountMax or 0,face[0],face[1],face[2])
bc=ceil(log(amountMax,2)/8)
fileO.write(bc.to_bytes(1,"little")+len(vertices).to_bytes(4,"little")+len(faces).to_bytes(4,"little"))
for vertex in vertices: fileO.write(vertex)
for face in faces: fileO.write(face[0].to_bytes(bc,"little")+face[1].to_bytes(bc,"little")+face[2].to_bytes(bc,"little"))
fileO.close()