io.py 文件源码

def read_files(*file_paths):
    files = []
    for i, p in enumerate(file_paths):
        if p:
            files.append(open(p, mode="r"))
            print 'Opened:', p
        else:
            files.append(EmptyFile())
            print 'WARNING: no path provided for file {} in list.'.format(i)

    with contextlib.nested(*files) as entered_files:
        for lines in izip(*entered_files):
            yield lines