Datas de Fusos em Python PyNorte - Nilo Menezes 

Por que datas e fusos? • Na região Norte temos 3 fusos horários • Se considerarmos o resto do país, teremos de 4 a 5 fusos dependendo do horário de verão • A Internet faz a manipulação de datas se tornar um problema frequente e normal 

Fusos 

E Python? • Módulo datetime • date • time • datetime • timedelta • pytz 

Detalhes • Para trabalhar com fuso horários, você precisa de datetime. Uma data sozinha não tem fuso. A hora sozinha também não 

Primeiros passos • Nomes de zona: >>> import pytz >>> from datetime import * >>> pytz.country_timezones["br"] ['America/Noronha', 'America/Belem', 'America/Fortaleza', 'America/Recife', 'America/Araguaina', 'America/Maceio', 'America/Bahia', 'America/Sao_Paulo', 'America/Campo_Grande', 'America/Cuiaba', 'America/Santarem', 'America/Porto_Velho', 'America/Boa_Vista', 'America/Manaus', 'America/Eirunepe', ‘America/Rio_Branco’] >>> manaus=pytz.timezone(“America/Manaus”) >>> datetime.now(tz=manaus) datetime.datetime(2016, 2, 6, 12, 42, 9, 901063, tzinfo=) >>> [k for k in pytz.all_timezones if k.startswith("Br")] ['Brazil/Acre', 'Brazil/DeNoronha', 'Brazil/East', 'Brazil/West'] 

Convertendo • Hora sem informação de zona >>> datetime.now() datetime.datetime(2016, 2, 6, 17, 42, 15, 818676) • Adiciona informação de zona >>> datetime.now(tz=pytz.utc) datetime.datetime(2016, 2, 6, 16, 42, 30, 365507, tzinfo=) 

Criando as zonas >>> manaus = pytz.timezone(“America/Manaus”) >>> belem = pytz.timezone(“America/Belem”) >>> datetime.now(tz=belem) datetime.datetime(2016, 2, 6, 13, 45, 20, 764109, tzinfo=) datetime.now(tz=manaus) datetime.now(tz=pytz.utc) datetime.now() 

Convertendo >>> agora = datetime.now(tz=pytz.utc) datetime.datetime(2016, 2, 6, 16, 46, 29, 808149, tzinfo=) >>> agora.astimezone(manaus) datetime.datetime(2016, 2, 6, 12, 46, 29, 808149, tzinfo=) >>> agora.astimezone(belem) datetime.datetime(2016, 2, 6, 13, 46, 29, 808149, tzinfo=) >>> manaus.normalize(agora) datetime.datetime(2016, 2, 6, 12, 46, 29, 808149, tzinfo=) >>> belem.normalize(agora) datetime.datetime(2016, 2, 6, 13, 46, 29, 808149, tzinfo=) 

Operações timedelta(minutes=5) >>> agora = datetime.now(tz=manaus) datetime.datetime(2016, 2, 6, 12, 49, 16, 798101, tzinfo=) >>> agora + timedelta(minutes=10) datetime.datetime(2016, 2, 6, 12, 59, 16, 798101, tzinfo=) >>> agora2 = datetime.now(tz=belem) datetime.datetime(2016, 2, 6, 13, 50, 9, 78355, tzinfo=) >>> agora2 - agora datetime.timedelta(0, 52, 280254) 

python-dateutil >>> from dateutil.relativedelta import relativedelta >>> datetime.now(tz=pytz.utc) + relativedelta(months=1) datetime.datetime(2016, 3, 6, 16, 51, 55, 811080, tzinfo=) >> datetime.now(tz=pytz.utc) + relativedelta(day=31, months=2) datetime.datetime(2016, 4, 30, 16, 52, 31, 801024, tzinfo=) 

Próximos hangouts >>> from dateutil.rrule import * >>> from datetime import datetime >>> list(rrule(MONTHLY, count=4, byweekday=(SA(+1)), dtstart=datetime.now())) [datetime.datetime(2016, 2, 6, 18, 4, 52), datetime.datetime(2016, 3, 5, 18, 4, 52), datetime.datetime(2016, 4, 2, 18, 4, 52), datetime.datetime(2016, 5, 7, 18, 4, 52)] • python-dateutil: • Autor: Gustavo Niemeyer • https://labix.org/python-dateutil 

Obrigado ! próximo hangout: 05/03/2016