1ヶ月分のカレンダーを表示する（その2）

calendar2.py

# -*- coding: utf-8 -*-

import sys

try:
    xrange
except NameError:
    xrange = range


def generate_days(ndays, wday):
    """
    1ヶ月分の日を生成するジェネレータ関数。
    たとえば generate_days(30, 2) だと、
      None, None, 1, 2, 3, ..., 28, 29, 30, None, None, None
    を生成する。
    """
    for _ in xrange(wday):
        yield None
    for i in xrange(1, ndays+1):
        yield i
    n = (wday + ndays) % 7
    if n < 7:
        for _ in xrange(7 - n):
            yield None

def generate_weeks(ndays, wday):
    """
    1ヶ月分のデータを生成するジェネレータ。
    たとえば build_month(30, 2) なら
       [None, None,    1,    2,    3,   4,     5],
       [   6,    7,    8,    9,   10,   11,   12],
       [  13,   14,   15,   16,   17,   18,   19],
       [  20,   21,   22,   23,   24,   25,   26],
       [  27,   28,   29,   30, None, None, None]
    を生成する。
    """
    week = []
    for x in generate_days(ndays, wday):
        week.append(x)
        if len(week) == 7:
            yield week
            week = []
    assert week == []

def render_weeks(weeks):
    """
    1ヶ月分のデータを受け取り、HTMLテーブルを返す。
    """
    buf = []
    buf.append('''<table>
  <thead>
    <th>Mon</th>
    <th>Tue</th>
    <th>Wed</th>
    <th>Thu</th>
    <th>Fri</th>
    <th>Sat</th>
    <th>Sun</th>
  </thead>
  <tbody>
''')
    for week in weeks:
        buf.append(     '    <tr>\n')
        for day in week:
            s = '' if day is None else str(day)   # or: s = str(day or '')
            buf.extend(('      <td>', s, '</td>\n'))
        buf.append(     '    </tr>\n')
    buf.append(       '''  </tbody>
</table>
''')
    return "".join(buf)


def print_calendar_month(ndays, wday):
    """
    1ヶ月分のカレンダーを出力する。
    """
    html = render_weeks(generate_weeks(ndays, wday))
    print(html)


if __name__ == '__main__':
    print_calendar_month(30, 2)