GPS heading in Python -

i working on gps project in python , need help. can't figure out how heading part work. want statement true heading of e.g. 355 degrees +/- bit of error. problem getting around 360 degrees. like

if ((heading – headerror) % 360) <= gps.heading <= ((heading + headerror) % 360): 

if use heading of 355 error of 20 , gps reads 4 , both north.

335 <= 4 <= 15 

how can check if it's in range of 335 15 335 360, 0 15?

one simple implementation:

def between(head, low, high):     """whether heading head between headings low , high."""     head, low, high = map(lambda x: x % 360, (head, low, high))     if high >= low:         return low <= head <= high     return low <= head < 360 or 0 <= head <= high 

first converts arguments headings between 0 , 360, determines situation we're in, whether can simple comparison, or need account 0/360. in latter case, explicitly checks between low value , 360 , between 0 , high value.

in use:

>>> between(4, 355-20, 355+20) true 

you refactor use e.g. equal(4, 355, 20) if wanted.