convert string to double gives nil - swift

Question

I'm parsing a text file to get the latitude and longitude of locations. I need to convert the lon/lat strings to doubles, but I can't do it.
I've tried both the Double(String) method and the (String as NSNumber).doubleValue. It always gives nil.
When I type in the numbers manually it works.
Here's the code snippet:
var items = [[String]]()
func readParkingData() {
guard let filepath = Bundle.main.path(forResource: "parking", ofType: "txt") else {
print("file not found")
return
}
print("file path : \(filepath)")
do{
let content = try String(contentsOfFile: filepath, encoding: .utf8)
let attributed = content.htmlAttributedString
let decoded : String = attributed!.string
let split = decoded.split(separator: ";")
var count = 0
var item = [String]()
for word in split {
item.append(String(word))
count += 1
if count == 30 {
items.append(item)
item = [String]()
count = 0
}
}
for entry in items {
print(entry[24])
print(entry[25])
let latString : String = entry[24]
let lonString : String = entry[25]
print(type(of: latString))
let lat = Double(latString)
print(lat)
}
}catch{
print("file read error \(filepath)")
}
}
I've looked through the other answers. The type of latString is String, not optional. Trimming white spaces didn't help either. lat is always nil.
What's going on here?

Answer 1

Apparently the floating point numbers are enclosed in quotation marks,
so you'll need not only trim whitespace but also quotation marks. Example:
let latString = "\"12.34\""
print(latString) // "12.34"
var cs = CharacterSet.whitespaces
cs.insert("\"")
let trimmedLatString = latString.trimmingCharacters(in: cs)
print(trimmedLatString) // 12.34
print(Double(trimmedLatString)!) // 12.34
Further remarks:
I do not see the reason to operate on the htmlAttributedString, you
probably should split the original content into lines and fields.
Is your input a CSV-formatted file? There are open source CSV reader libraries
which you might try.