How to separate string with latitude and longitude

Question

I have this location string with latitude and longitude.

location = "-40.20361-40.20361"

What I would like to do is separate the string as

lat = "-40.20361"
long = "-40.20361"

Note: The location can also take the following forms so I'm looking for a solution that works regardless of the notation.

"+40.20361+40.20361"
"-40.20361+40.20361"
"+40.20361-40.20361"

Thanks.

Answer 1

You can do it either with string manipulation (split string on - and +) or as a regular expression. A regular expression solution could be something like:

>>> lat, lon = re.match(r'([+-][0-9]{1,3}\.[0-9]+)([+-][0-9]{1,3}\.[0-9]+)', '+40.20361-40.20361').groups()
>>> lat, lon
('+40.20361', '-40.20361')

The regular expression consists of two patterns of '([+-][0-9]{1,3}\.[0-9]+). To break this down further:

([+-][0-9]{1,3}\.[0-9]+)
  ^- match the prefix (i.e. + or -)

([+-][0-9]{1,3}\.[0-9]+)
           ^--- between 1 and 3 (inclusive) repeats of the class in front,
                so [0-9] repeated one to three times

([+-][0-9]{1,3}\.[0-9]+)
                ^-- a literal dot (otherwise a dot means "any character")

([+-][0-9]{1,3}\.[0-9]+)

                      ^-- repeat the preceding character class at least once, so
                      at least one occurence of [0-9].

Answer 2

If you want to avoid regular expressions, thats my solution:

def location_split (location):
    lat=""
    lon=""
    split=False
    for i, char in enumerate(location):
        if char in "+-" and i!=0:
            split=True
        if split==False:
            lat+=char
        else:
            lon+=char
    
    return (lat, lon)

print (location_split("+40.20361+40.20361")) # ('+40.20361', '+40.20361')
print (location_split("-40.20361+40.20361")) # ('-40.20361', '+40.20361'
print (location_split("+40.20361-40.20361")) # ('+40.20361', '-40.20361')