listing20-2.py

《Beginning Python--From Novice to Professional》 的源码

def lines(file):
    for line in file: yield line
    yield '\n'

def blocks(file):
    block = []
    for line in lines(file):
        if line.strip():
            block.append(line)
        elif block:
            yield ''.join(block).strip()
            block = []