Python unpack string in to array

Question

I am working with Ruby every day, but i have an issue in Python. I was found this languages very similar... But I have some problems with migration from Ruby :)

Please, help me to convert this action in python:

   string = "qwerty2012"
   (var, some_var, another_var)  = string.unpack("a1a4a*")

this should return three variables with unpacked values from string:

   var         = "q"      # a1
   some_var    = "wert"   # a4
   another_var = "y2012"  # a*

Help me to represent it in Python Thank you!

Answer 1

s = "qwerty2012"
(a, b, c) = s[:1], s[1:5], s[5:]

Answer 2

Python does have a similar module named struct. It lacks the ability to grab the rest of the string in the same way that Ruby and PHP lifted from Perl. You can almost get there though:

>>> import struct
>>> s = 'qwerty2012'
>>> struct.unpack_from('1s4s', s)
('q', 'wert')
>>> def my_unpack(format, packed_string):
...    result = []
...    result.extend(struct.unpack_from(format, packed_string))
...    chars_gobbled = struct.calcsize(format)
...    rest = packed_string[chars_gobbled:]
...    if rest:
...        result.append(rest)
...    return result
...
>>> my_unpack('1s4s', 'qwerty2012')
['q', 'wert', 'y2012']
>>> my_unpack('1s4s', 'qwert')
['q', 'wert']
>>> [hex(x) for x in my_unpack('<I', '\xDE\xAD\xBE\xEF')]
['0xefbeadde']

I wish that the struct module implemented the rest of Perl's unpack and pack since they were incredibly useful functions for ripping apart binary packets but alas.