Convert a Python int into a big-endian string of bytes

You can use the struct module:

import struct
print(struct.pack('>I', your_int))

'>I' is a format string. > means big endian and I means unsigned int. Check the documentation for more format chars.

In Python 3.2+, you can use int.to_bytes:

If you don't want to specify the size

>>> n = 1245427
>>> n.to_bytes((n.bit_length() + 7) // 8, 'big') or b'\0'
b'\x13\x00\xf3'

>>> (1245427).to_bytes(3, byteorder='big')
b'\x13\x00\xf3'

This is fast and works for small and (arbitrary) large ints:

def Dump(n): 
  s = '%x' % n
  if len(s) & 1:
    s = '0' + s
  return s.decode('hex')
print repr(Dump(1245427))  #: '\x13\x00\xf3'