#!/usr/bin/python import fileinput a = fileinput.FileInput() def window_iterate(sequence, width=2, begin=0): while begin < len(sequence): result = sequence[begin:begin+width] while len(result) < width: result.append('') yield result begin += 1 for line in a: line = line.split() out = [] for window in window_iterate(line): if window[0] in set(['a', 'an']): if any(window[1].startswith(vowel) for vowel in 'aeiou'): if window[0] != 'an': if raw_input('change article in %r? ' % ' '.join(window)).lower().startswith('y'): window[0] = 'an' else: if window[0] != 'a': if raw_input('change article in %r? ' % ' '.join(window)).lower().startswith('y'): window[0] = 'a' out.append(window[0]) print(' '.join(out))