How do I shift the decimal place in Python?

问题

I'm currently using the following to compute the difference in two times. The out - in is very fast and thus I do not need to display the hour and minutes which are just 0.00 anyway. How do I actually shift the decimal place in Python?

def time_deltas(infile): 
    entries = (line.split() for line in open(INFILE, "r")) 
    ts = {}  
    for e in entries: 
        if " ".join(e[2:5]) == "OuchMsg out: [O]": 
            ts[e[8]] = e[0]    
        elif " ".join(e[2:5]) == "OuchMsg in: [A]":    
            in_ts, ref_id = e[0], e[7] 
            out_ts = ts.pop(ref_id, None) 
            yield (float(out_ts),ref_id[1:-1], "%.10f"%(float(in_ts) - float(out_ts)))

INFILE = 'C:/Users/kdalton/Documents/Minifile.txt'
print list(time_deltas(INFILE))

回答1:

The same way you do in math

a = 0.01;
a *= 10; // shifts decimal place right
a /= 10.; // shifts decimal place left

回答2:

or use the datetime module

>>> import datetime
>>> a = datetime.datetime.strptime("30 Nov 11 0.00.00", "%d %b %y %H.%M.%S")
>>> b = datetime.datetime.strptime("2 Dec 11 0.00.00", "%d %b %y %H.%M.%S")
>>> a - b
datetime.timedelta(-2)

来源：https://stackoverflow.com/questions/8362792/how-do-i-shift-the-decimal-place-in-python