from pysword import SPCSWO

# Parse the product text (the WWUS0n PTSDYn product, where n = 1,2,3).
swo = SPCSWO(outlook_text)

# Load the text from a local file.
swo = SPCSWO.read('/path/to/ptsdyn.txt')

# Download from the Internet. WWUS0n PTSDYn products exist back to 24 March 2005.
from datetime import datetime

outlook_issue = datetime(2012, 4, 13, 6, 0, 0)             # Outlook issuance time
lead_time = 2                                              # Lead time in the outlook in days
swo = SPCSWO.download(outlook_issue, lead_time=lead_time)  # lead_time defaults to 1 day if not specified.

# Do stuff with the outlook
product = swo['categorical']          # Pull out the categorical outlook (specify 'tornado' for the 
                                      #    tornado outlook, 'hail' for the hail outlook, 'wind' for
                                      #    the wind outlook, or 'any severe' for probability of any
                                      #    severe on days 2 and 3.).
contour_vals = product.contour_vals   # Get the contour values for this outlook
prod_name = product.name              # Get the product name ('categorical', 'tornado', etc.)
for con_val in contour_vals:
    for polygon in product[con_val]:       # Loop over all contours (e.g. all SLGT risk areas)
        # polygon is a shapely polygon representing a contour in the outlook. The vertices are lon, lat
        # coordinates. You can use shapely.ops.transform() and basemap to transform to x, y coordinates.