Python处理时间

from dateutil.parser import parse
a = parse(‘2011-01-03’)
print(a)

from dateutil.parser import parse
a = parse(‘Jan 31,1997 10:45 PM’)
print(a)

from dateutil.parser import parse
a = parse(‘6/12/2011’,dayfirst = True)
print(a)

时间做索引，算数运算会按照日期运算自动对齐

from datetime import datetime
import pandas as pd
import numpy as np
dates = [datetime(2011,1,2),datetime(2011,1,5),datetime(2011,1,7),datetime(2011,1,8),datetime(2011,1,10),datetime(2011,1,12)]
ts = pd.Series(np.random.rand(6),index=dates)
print(ts)
a = ts + ts[::2]
print(a)

from datetime import datetime
import pandas as pd
import numpy as np
longer_ts = pd.Series(np.random.rand(1000),index=pd.date_range(‘1/1/2000’,periods=1000))
print(longer_ts.truncate(after=’1/9/2001’))

from datetime import datetime
import pandas as pd
import numpy as np
dates = [datetime(2011,1,2),datetime(2011,1,5),datetime(2011,1,7),datetime(2011,1,8),datetime(2011,1,10),datetime(2011,1,12)]
ts = pd.Series(np.random.rand(6),index=dates)
print(ts)
a = ts.resample(‘D’).sum()
print(a)

a = pd.date_range(‘1/1/2000’,’1/3/2000 23:59’,freq=’4h’)
print(a)