dateutilを使う
サンプルコード
import datetime$
import sys$
import logging$
$
def cal_test(value):$
try:$
from dateutil import relativedelta$
d = datetime.date(2010,1,1)$
result = d + relativedelta.relativedelta(months=value, day=99)$
print 'result = %s' % result$
return result$
$
except:$
logging.error('%s', sys.exc_info())$
raise$
$
if __name__== "__main__":$
try:$
logging.getLogger().setLevel(logging.DEBUG)$
argvs = sys.argv$
print 'argvs:%s' % argvs$
cal_test(int(argvs[1]))$
except:$
logging.error('%s', sys.exc_info())$
raise$
結果
argvs:['datet.py', '1']
result = 2010-02-28
参考リンク：