functions.py 文件源码

def index_file(filename):
    """Reads a datafile and returns a dict index
    of the starting lines for each year and lists of starting lines for each
     month over each year.
    """

    import calendar

    _reads = 0
    _return_dict = {}

    with open(filename, 'r') as _data_file:

        _last_year = ''
        _last_month = ''

        for _data_line in _data_file:

            _reads += 1

            try:
                _year = str(_data_line[13:17])
                _month = calendar.month_abbr[int(_data_line[17:19])]

                if _year != _last_year:
                    _return_dict[_year] = _reads - 1
                    _last_year = _year

                if _month != _last_month:
                    try:
                        _return_dict[_month].append(_reads - 1)
                    except KeyError:
                        _return_dict[_month] = [_reads - 1]
                    _last_month = _month

            except ValueError:
                continue

    return _return_dict