in scripts/reader/preprocess.py [0:0]
def find_answer(offsets, begin_offset, end_offset):
"""Match token offsets with the char begin/end offsets of the answer."""
start = [i for i, tok in enumerate(offsets) if tok[0] == begin_offset]
end = [i for i, tok in enumerate(offsets) if tok[1] == end_offset]
assert(len(start) <= 1)
assert(len(end) <= 1)
if len(start) == 1 and len(end) == 1:
return start[0], end[0]