python学习笔记：datetime使用小结

一些与datetime相关的函数的使用。。。。

import localeimport datetimeone_day = datetime.timedelta(days=1)def get_year_and_month_from_date(date):    year_and_month = date.strftime('%Y-%m')    assert len(year_and_month) == 7    return year_and_monthdef get_date_from_date_string(date_string):    date_array = date_string.split('-')    year, month, day = map(int, date_array)    return datetime.date(year, month, day)# Number of days per month (except for February in leap years)month_days = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] def isleap(year):    """Return 1 for leap years, 0 for non-leap years."""    return year % 4 == 0 and (year % 100 != 0 or year % 400 == 0)def get_number_of_days(year, month):    '''     Return the number of days in a given month of a given year    '''    days = month_days[month] + (month == 2 and isleap(year))    return daysdef format_date(format_string, date=None):    if date is None:        date = datetime.datetime.now()    try:        date_string = date.strftime(format_string)    except ValueError:        # This happens if the format string ends with "%"        date_string = _('Incorrect date format')    # Turn date into unicode string    locale_name, locale_encoding = locale.getlocale()    # locale_encoding may be None may if the value cannot be determined    locale_encoding = locale_encoding or 'UTF-8'    date_string = date_string.decode(locale_encoding, 'replace')    return date_string