#!/usr/bin/env python

"""

Below are two techniques showing how to reformat an address.

The functions below check an address to see if it has a direction

at the end of the address; if so, they reformat the address so the

direction appears before the street name.

The first function uses indexing and slice notation

to pull apart the address. The second function uses a

regular expression to parse the address.

USAGE:

>>> parse_address("123 Main St N")

'123 N Main St'

>>> parse_address_with_regex("123 Main St N")

'123 N Main St'

"""

import re

#### Index/Slice Technique ####

def parse_address(address):

"""

This function, courtesy of Brian Bowling, uses slice notation to parse and reformat an address.

More info on slice notation is here:

http://docs.python.org/tutorial/introduction.html#strings

"""

# find the first and last spaces in the string

last_space = len(address) - 1

first_space = 0

while address[last_space] != " ":

last_space -= 1

while address[first_space] != " ":

first_space += 1

# test to see if the characters following the last space are a direction

if address[last_space + 1:] in ("N", "S", "E", "W", "NE", "NW", "SE", "SW"):

# make the transformation

new_address = address[:first_space] + address[last_space:] + address[first_space:last_space]

else:

new_address = address

return new_address

#### Regular Expression Technique ####

# Create a regular expression pattern, which we'll use to match address strings

address_pattern = re.compile(r'^(\w+)\s(.+?)\s(N|S|E|W|NW|NE|SW|SE)$')

def parse_address_with_regex(address_string):

"""

This function uses a regular expression to parse and reformat an address.

More info on regular expressions are here:

http://docs.python.org/library/re.html

"""

# Try matching the address_string against the address_pattern

regex_match = address_pattern.match(address_string.strip())

if regex_match:

# If there's a match, then assign the address components to variables

number, address, direction = regex_match.groups()

# Reformat the address components into a new string

new_address = "%s %s %s" % (number, direction, address)

else:

new_address = address_string

return new_address

if __name__ == '__main__':

# The "doctest" code at the bottom of this program is boilerplate syntax

# to help run tests inside of Python docstrings.

# Doctests not only help ensure that your code works as expected,

# but they help demonstrate to others how to properly use your code.

# These tests resemble the code from a session in the Python

# interactive interpreter, and in fact, you can copy and paste code from

# such sessions directly into your Python program.

#

# The doctests in this program are at the top of the file, right beneath

# the "Usage" line. To run the doctests in this program, execute the

# following command from your shell or terminal:

# python address_parser.py -v

# More info on doctests can be found here:

# http://docs.python.org/library/doctest.html

import doctest

doctest.testmod()