How common is your city name? Use Census data to find out.

city-getter.sh

city=$1

if [[ -n "$city" ]]; then
    echo "$city"
    wget -q -O states.txt -nc http://www2.census.gov/geo/docs/reference/state.txt
    echo "Fetched state file"
    wget -q -O places.txt -nc http://www2.census.gov/geo/docs/reference/codes/files/national_places.txt
    echo "Fetched national places file"
    csvjoin -e "iso-8859-1" -d "|" -c 2,1 places.txt states.txt | csvcut -c 8,9,10,7,4,3 | csvsort -c 6 | csvformat -D "|" > places_with_state_names.txt
    echo "Merged place file with states"
    national_count=$(wc -l < places.txt)
    joined_count=$(wc -l < places_with_state_names.txt)
    if [[ $national_count -eq $joined_count ]]; then
        echo "Line counts match: $national_count" | xargs
        echo "Grabbing $city data ..."
        fab getCities:"$city"
    else
        echo "Line counts don't match. Places: $national_count / Joined: $joined_count" | xargs
    fi
else
    echo "Pass a city name as an argument: sh city-getter.sh \"Rock Springs\""
fi

fabfile.py

import os
import csv
import json
import fabric
import requests
from slugify import slugify
import time

fabric.state.output.status = False

def getCities(city_name):
    base_api_url = "http://api.census.gov/data/2010/sf1?get=P0010001&for=place:"
    mid_api_url = "&in=state:"
    post_api_url = "&key=" + os.environ['CENSUS_API_KEY']

    slugified_name = slugify(city_name).lower()
    with open("places_with_state_names.txt", "rb") as infile, \
         open(slugified_name + ".csv", "wb") as outfile:
        reader = csv.DictReader(infile, delimiter='|')
        headers = reader.fieldnames
        headers.append('POP_2010')
        writer = csv.DictWriter(outfile, fieldnames=headers)
        writer.writeheader()
        counter = 0
        for row in reader:
            if city_name.upper() in row['PLACENAME'].upper():
                urlstring = (base_api_url + row['PLACEFP'] + mid_api_url +
                             row['STATE'] + post_api_url)
                print "Fetching population data for", row['PLACENAME'], row['STATE_NAME']
                r = requests.get(urlstring)
                response = r.json()
                pop_2010 = response[1][0]
                row['POP_2010'] = pop_2010
                writer.writerow(row)
                counter += 1
                time.sleep(1)
        print "Found", counter, "matches"