I am very new to Python. I have a function DISTANCE(lat1, long1, lat2, long2) that calculates the distance between 2 points.
Then I have a list called POINTS, where each value is another list which contains those four values.
I would like to obtain the sum of the results of the function DISTANCE for all the values inside POINTS.
Can anybody help me with that? Thanks!
sum(DISTANCE(*p) for p in POINTS)
The * here is the syntax for Unpacking Argument Lists, also called the splat operator. This passes the contents of an iterable as the positional arguments to a function, so if p were [1, 2, 3, 4], DISTANCE(*p) would be the same as DISTANCE(1, 2, 3, 4).
How about:
totalDistance = sum(DISTANCE(lat1, long1, lat2, long2) for (lat1, long1, lat2, long2) in POINTS)
sum([DISTANCE(*args) for args in POINTS])
What this one-liner does is use a list comprehension on POINTS, applying each item in it as a list to DISTANCE, like this:
args = [1, 2, 3, 4]
DISTANCE(*args) == DISTANCE(1, 2, 3, 4)
The call to sum takes a list itself and returns the sum of all the items within.
A side suggestion: name your functions in all lowercase. PEP 8 has a lot of good style suggestions for making readable Python code.
use for-in loop if you're new to python:
result=[]
for item in POINTS:
res=DISTANCE(*item)
result.append(res)
print(sum(result))
if you're confused about what's * here, you should read this
