Question

I just read about the *args and **kwargs notation in python and decided to use it with my functions that use struct.pack as such:

def pack_floats(*args):

   return struct.pack('%df' %len(args), args)

But of course, it doesn’t work because args is a tuple. If I wanted to pack three numbers, I would call pack as such

struct.pack('3f', 1, 2, 3)

Alternatively I could just run it through a loop and pack one number at a time, but I don’t know whether there is any performance difference between one value at a time vs all values at a time.

Is there a way to write the pack_floats function without calling the pack function inside a loop?

Answer 1

>>> import struct
>>> def pack_floats(*args):
...     return struct.pack('%df' %len(args), *args)
... 
>>> pack_floats(0.1,1.2,2.3)
'\xcd\xcc\xcc=\x9a\x99\x99?33\x13@'