from dateutil.parser import parse

a=20170825
b=str(a)
c=parse(b)

from matplotlib.pylab import date2num
 e = date2num(c)

e
Out[30]: 736566.0

d=str(c)

d
Out[25]: '2017-08-25 00:00:00'

from matplotlib.pylab import date2num
 
timeArray = time.strptime(d, "%Y-%m-%d %H:%M:%S")

timeArray
Out[27]: time.struct_time(tm_year=2017, tm_mon=8, tm_mday=25, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=4, tm_yday=237, tm_isdst=-1)

timestamp = time.mktime(timeArray)

timestamp
Out[29]: 1503590400.0