[Tutor] simular function to pack (perl)

[Michael P. Reilly]

> Hello erverybody,
> 
> are there simular function to pack and unpack (perl) in python.
> 
> Thanks
> 
> Wolfgang

In Python, it is the struct module.

import struct
datastruct = 'ff2xh'                # the data structure format
s_sz = struct.calcsize(datastruct)  # how many bytes in the structure
f = open('form.dat', 'rb')
graph_points = {}
block = f.read(s_sz)   # read the first structure from the binary file
                       # into a character string
while block:
  # decode the structure from the character string
  (x, y, count) = struct.unpack(datastruct, block)
  graph_points[x,y] = count
  block = f.read(s_sz)
f.close()
# do something with graph_points

References:
Python Library Reference manual, section 4.3 - struct
  <URL: http://www.python.org/doc/current/lib/module-struct.html>

  -Arcege

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