实现这4条线的最Pythonic方式？

Question

I have a csv cell value, row[13] that contains the following text: POINT (174.29635 -41.60557)

I need to strip out the text and brackets, and convert the two numbers to float, each assigned to a var:-

geo_pair = row[13].replace("POINT (", "")
geo_pair = geo_pair.replace(")", "")
self.longitude, self.latitude = geo_pair.split(" ")
self.longitude, self.latitude = float(self.longitude), float(self.latitude)

I'm pretty sure there is a cleaner way of doing this, and I wondered what someone who knows what they are doing would do!

Answer 1

Since the format is fixed and consists of prefix, data, and suffix, I would use slicing to remove prefix and suffix: map(float, s[7:-1].split()) .

This is clear and simple at the same time:

>>> s = "POINT (174.29635 -41.60557)"
>>> longitude, latitude = map(float, s[7:-1].split())

This also works upon sign changes or when the number of decimal places changes.

And by the way, as long as you are not parsing tons of input, it does not really matter which way to chose. It's mostly a matter of taste and most likely not performance-critical in your case. So don't spend too much time with this :-).

Answer 2

Use the regex?

>>> map(float, re.search(r'\((.*)\)', s).group(1).split())
[174.29635, -41.60557]
>>> 

Answer 3

How about this?

>>> a, b = map(float, row.translate(None, "POINT()").split())
>>> a
174.29635
>>> b
-41.60557

where

row = "POINT (174.29635 -41.60557)"

Answer 4

I use split(sep1, 1)[-1].split(sep2, 1)[0] :

geo_pair = row[13].split("POINT (", 1)[-1].split(")", 1)[0]
self.longitude, self.latitude = map(float, geo_pair.split())