You may work with one partner on this assignment. If you work with a partner, put your name and the name of your partner in the list of authors at the top of your program. Only one partner needs to run handin21 to submit the files for the group. Both partners will receive the same grade.
Some of the problems will have optional components that allow you to
further practice your skills in Python. Optional portions will not be
graded, but may be interesting for those wanting some extra challenges.
Run update21, if you haven't already, to create the cs21/labs/10 directory. Then cd into your cs21/labs/10 directory and create the python programs for lab 10 in this directory (handin21 looks for your lab 10 assignments in your cs21/labs/10 directory):
$ update21 $ cd cs21/labs/10 $ vim zipcode.py
The file /usr/local/doc/zipcodes.txt contains the data you need to write your program. Each line of the file contains seven fields separated by commas representing the ZIP code, latitude, longitude, city name, county name, state, and population, respectively. The entry for Swarthmore is shown below:
The full file has entries for 41824 unique ZIP codes. You can open up the file in vim or any other text editor if you would like to look at the file in more detail. When you read in a line from this file in python you can use line.split(",") to separate the line into a list of strings.
Your program should prompt the user for two cities. The user can lookup a city by ZIP code or by a city name and its two letter state abbreviation. For each city, display the following information:
In addition to the information above, display the distance between the two cities the user typed.
A sample run is shown below:
$ python zipcodes.py @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ This program creates a database of information about cities A user can then enter information about two cities (either by zipcode or by city and state) and get the distance between them. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ --------------------------------------------------- City #1: Enter a zipcode or a city,state: 53703 City, State, Zip: Madison,WI, 53703 County: Dane Population: 249307 Lat/Long: 43.08/-89.38 The closest large city is Rockford,IL (pop: 188073, dist: 53.15 miles) City #2: Enter a zipcode or a city,state: Swarthmore,PA City, State, Zip: Swarthmore,PA, 19081 County: Delaware Population: 9907 Lat/Long: 39.90/-75.35 The closest large city is Philadelphia,PA (pop: 1517913, dist: 6.07 miles) Distance between Madison,WI and Swarthmore,PA is 758.47 miles Check more locations? (yes,no): yes --------------------------------------------------- City #1: Enter a zipcode or a city,state: 19081 City, State, Zip: Swarthmore,PA, 19081 County: Delaware Population: 9907 Lat/Long: 39.90/-75.35 The closest large city is Philadelphia,PA (pop: 1517913, dist: 6.07 miles) City #2: Enter a zipcode or a city,state: 59453 City, State, Zip: Judith Gap,MT, 59453 County: Wheatland Population: 307 Lat/Long: 46.68/-109.64 The closest large city is Billings,MT (pop: 112078, dist: 77.76 miles) Distance between Swarthmore,PA and Judith Gap,MT is 1773.76 miles Check more locations? (yes,no): yes --------------------------------------------------- City #1: Enter a zipcode or a city,state: San Francisco,CA City, State, Zip: San Francisco,CA, 94101 County: San Francisco Population: 776733 Lat/Long: 37.78/-122.73 The closest large city is Daly City,CA (pop: 110768, dist: 15.19 miles) City #2: Enter a zipcode or a city,state: Boston,MA City, State, Zip: Boston,MA, 02101 County: Suffolk Population: 359585 Lat/Long: 42.37/-71.03 The closest large city is Cambridge,MA (pop: 101391, dist: 2.94 miles) Distance between San Francisco,CA and Boston,MA is 2712.36 miles Check more locations? (yes,no): no okay, check you later
If you cannot find an entry for a particular city or ZIP code, inform the user that you cannot find that location and prompt them to enter another location.
zipinfo = ["19081", 39.897562, -75.346584, "Swarthmore", "Delaware", "PA", 9907]Note that some elements in this list have quotes to indicate they are strings while numeric elements do not have quotes. When you use line.split(",") when reading an input line from the file, latitude, longitude, and population will not be automatically converted to numeric types. Instead, you need to process the split list to convert some buckets from strings to other types. To convert the string in bucket i to a float you can do something like this:
zipinfo[i] = float(zipinfo[i])
allZips =  # a list allZips.append(zipinfo) # add a list as the first item to allZips print len(allZips) # what is this? 7? 1? 2? something else? location = allZips # a list with zip, lat, long, .... print location # prints SwarthmoreIf you read the file zipcodes.txt sequentially, the lines are sorted by increasing zipcode. You must preserve this order in you list of all locations. The resulting list of lists might look like this (allZips list is drawn on its side):
allZips | | \/ ------ 0 | --|---> ["00501",40.922326,-072.637078,"Holtsville","Suffolk","NY",12119] ------ 1 | --|---> ["00544",40.922326,-072.637078,"Holtsville","Suffolk","NY",12119] ------ 2 | --|---> ["01001",42.070610,-072.620290,"Agawam ","Hampden","MA",16576] ------ | . | | . | | . | ------ n-2 | --|---> ["99929",56.409507,-132.338228,"Wrangell","Wrangell Petersburg","AK",2424] ------ n-1 | --|---> ["99950",55.875767,-131.466339,"Ketchikan","Ketchikan Gateway","AK",14066] ------
When searching on city and state, you will need to do a linear search and remember that you need to compare two bucket values in each list entry to find a match.
In addition to the requirements above, we have included some tips and problems to watch out for below.
Some large cities (Philadelphia, PA, for example) have multiple ZIP
codes. When asked to report a ZIP code for a city, you can decide how to
handle this. Possible options include reporting all ZIP codes for a
particular city, reporting the first ZIP code you find for that city,
reporting one example ZIP code and stating there are other possibilities,
or designing a method of your own choosing. You must report at least one
ZIP code for a city if it is in the list of known cities.
Be careful when reporting the closest city to a given city. Do not report
the same city. For example, the city with a population over 100,000
closest to Philadelphia, PA, should not be Philadelphia, PA, but some
other city. This is further complicated by the fact that many big cities
have multiple ZIP codes, when reporting the closest big city, ensure that
the city names are in fact different.
You should use the "great circle" distance formula to compute the distance between two cities. If the first city is at a geographic location (lat1, long1), and the second city is at (lat2, long2), then the distance between the two cities is given by the formula:
D = R acos( sin(lat1)sin(lat2) + cos(lat1)cos(lat2)cos(long2-long1))
Where R is the radius of the Earth (6371 km or 3963 miles), and acos is the inverse cosine. You can get this function by importing the math module in python. Note that each lat/long must be converted from degrees to radians before computing a sine or cosine. The formula for this conversion is
rad = deg*pi/180or use the python function radians imported from the math library.
This data file we have provided you is by no means complete. Some ZIP
codes were missing or did not have lat/long data and were removed. For
some cities, we did not have population data, so we set the population
arbitrarily to 0. If your favorite US city or hometown in the US is
missing and you know all the info (ZIP, city name, county name, state,
lat, long, and population), let us know and we will be happy to add a few cities, but we are not trying to maintain a comprehensive list.
Once you are satisfied with your program, hand it in by typing handin21 in a terminal window.