code: def inplace_filter(func, sequence):
  	
  	target = 0
  	for source in xrange(len(sequence)):
  		if func(sequence[source]):
  			sequence[target] = sequence[source]
  			target += 1
  	del sequence[target:]
docs: Like Python's filter() builtin, but modifies the sequence in place.
  
  	Example:
  
  	>>> l = range(10)
  	>>> inplace_filter(lambda x: x > 5, l)
  	>>> l
  	[6, 7, 8, 9]
  
  	Performance considerations:  the function iterates over the
  	sequence, shuffling surviving members down and deleting whatever
  	top part of the sequence is left empty at the end, so sequences
  	whose surviving members are predominantly at the bottom will be
  	processed faster.