在Python中将数字舍入到50,000

Question

How can I round a number to the nearest up or down 50 thousand?

I want to round this 542756 to this 550000 , or round this 521405 to this 500000 . Considering that the number to be rounded is a variable x .

I tried this:

import math

def roundup(x):
    return int(math.ceil(x / 50000.0)) * 50000

But it only round up and I need to round both up or down.

I also tried this:

round(float(x), -5)

But this round to the nearest hundred thousand.

I suppose there is a simple solution but couldn't find anything.

Answer 1

You can use:

def round_nearest(x,num=50000):
    return int(round(float(x)/num)*num)

You can also avoid converting to floating point if you deal with large numbers . In that case, you can use:

def round_nearest(x,num=50000):
    return ((x+num//2)//num)*num

You can call it with two arguments to round to the nearest num , or without will round to the nearest 50000. You can omit the int(..) if you do not want the result to be an int(..) per se (for instance if you want to round on 0.5 as well). In that case we can define:

def round_nearest(x,num=50000):
    return round(float(x)/num)*num

This produces:

>>> round_nearest(542756)
550000
>>> round_nearest(521405)
500000

Or if you want another number to round to:

>>> round_nearest(542756,1000)
543000
>>> round_nearest(542756,200000)
600000

Answer 2

def round_nearest(x, multiple):
    return math.floor(float(x) / multiple + 0.5) * multiple

>>> round_nearest(542756, 50000)
550000
>>> round_nearest(521405, 50000)
500000

Answer 3

divmod could be your friend in this case

def roundmynumber(x):
    y,z = divmod(x,50000)
    if z >25000: y +=1
    return int(50000*y)

>>> roundmynumber(83000)
100000
>>> roundmynumber(13000)
0
>>> roundmynumber(52000)
50000
>>> roundmynumber(152000)
150000
>>> roundmynumber(172000)
150000
>>> roundmynumber(152000.045)
150000
>>> roundmynumber(-152000.045)
-150000