''' Purpose: provide weather forecast by accessing US Weather Service web
             service

    Usage:   user provides a zipcode

    Output:  municipality and state combo along with its current forecast

    Note:    makes use of a csv web file adapted from www.boutell.com/zipcodes/
'''

# get url access capabilities
import urllib.request

# define weather.gov base query
WEATHER_GOV_QUERY = 'http://forecast.weather.gov/zipcity.php?inputstring='

# get zipcode of interest
zipcode = input( 'Enter zipcode: ' )

# specify complete query
query = WEATHER_GOV_QUERY + zipcode

# get a connection to the web resource of interest
stream = urllib.request.urlopen( query ) 

# read stream to get its contents
contents = stream.read()

# decode contents into plain text form
page = contents.decode( 'UTF-8' )

# forecast delimiters
OPENING_DELIMITER = 'forecast-text">'  # this string is in front of the forecast that we actually want
CLOSING_DELIMITER = '<' # this string is after the forecast we actually want

# to get the forecast, itself, we need to find the forecast
i = page.index( ... )
j = page.index( ... )

forecast = page[ i : j ]

print(forecast)