Question

I am new to Python. Is there a StringTokenizer in Python? Can I do character by character scanning and copying.

I have the following input string

data = '123:Palo Alto, CA -> 456:Seattle, WA 789'

I need to extract the two (city, state) fields from this string. Here is the code I wrote

name_list = []
while i < len(data)):
      if line[i] == ':':
          name = ''
          j = 0
          i = i + 1
          while line[i] != '-' and line[i].isnumeric() == False:
             name[j] = line[i]   # This line gives error
             i = i + 1
             j = j + 1
          name_list.append(name)
      i = i + 1

What should I do?

Answer 1

My take, assuming the string is always formatted as per your example:

import re

data = '123:Palo Alto, CA -> 456:Seattle, WA 789'

name_list = []
r = re.compile("(\s?\d)|:")
name_list += r.sub("", data).split(" ->")
print name_list # Prints ['Palo Alto, CA', 'Seattle, WA']

As a note on your error, the empty string will have a length of 0, so the index 0 doesn’t exist:

>>> s = ""
>>> len(s)
0

You can, however, concatenate strings in Python with the + operator, like so:

>>> s += "Some"
>>> s += " Text"
>>> print s
Some Text