set of functions to geolocate addresses and calculate distances betwe…

…en points using Google API, OSM API, and Census API

geocode.py

@@ -0,0 +1,161 @@
+import warnings
+try:
+    import censusgeocode as cg
+except:
+    warnings.warn("Module censusgeocode not available")
+import requests
+import time
+import pandas as pd
+import numpy as np
+
+
+def get_OSM(address):
+    '''
+    Geocodes given address using Open Street Map.
+
+    Returns
+    -------
+    r : dict
+        Query results under r['results'], and request status under r['status'].
+        If request fails r['status'] will be 'NOT_FOUND'
+    '''
+    base_url = 'https://nominatim.openstreetmap.org/search'
+    query = {
+        'q':address, #Free form string
+        'format':'json',
+        'polygon':1,
+        'addressdetails':1,
+        'namedetails':1
+    }
+    r = requests.get(base_url,params=query)
+    return {'results':r.json(),'status':('OK' if len(r.json())>0 else 'NOT_FOUND')}
+
+def get_census(address):
+    '''
+    Geocodes given address using census API.
+
+    Returns
+    -------
+    r : dict
+        Query results under r['results'], and request status under r['status'].
+        If request fails r['status'] will be 'NOT_FOUND'
+    '''
+    try:
+        r = cg.onelineaddress(address, returntype='locations')
+        return {'results':r,'status':('OK' if len(r)>0 else 'NOT_FOUND')}
+    except:
+        return {'results':[],'status':'NOT_FOUND'}
+
+class GAPI():
+    '''
+    Instanciated object can be used to query Google Geocoding API.
+
+    Parameters
+    ----------
+    KEY : str
+        Google Geocoding API KEY
+    debug : boolean (optional, default=False)
+        If True, it will not trigger a request.
+    '''
+    def __init__(self,KEY,debug=False,qLimit=35000):
+        self.base_url = 'https://maps.googleapis.com/maps/api/geocode/json'
+        self.distance_base_url = 'https://maps.googleapis.com/maps/api/distancematrix/json'
+        self.over_limit = False
+        self.GOOGLE_GEOCODING_API_KEY = KEY
+        self.debug = debug
+        self.time = time.time()
+        self.QPS = 50.
+        self.qLimit = qLimit
+        self.qCount = 0
+        self.pricePerQuery = 0.005
+
+    def money_spent(self):
+        '''
+        Amount of money spent in queries so far.
+        '''
+        print('Total of',self.qCount,'queries')
+        print('\tpaid',self.qCount*self.pricePerQuery,'USD')
+
+    def get(self,address):
+        '''
+        Geocodes given address using Google API.
+
+        Returns
+        -------
+        r : dict
+            Query results under r['results'], and request status under r['status'].
+            If request fails it will try until it goes through, unless its over query limit.
+            If KEY exceedes query limit, then r['status']='OVER_QUERY_LIMIT'
+        '''
+        query = {'address':address,'key':self.GOOGLE_GEOCODING_API_KEY}
+        if not self.over_limit:
+            r = self._get(self.base_url,params=query)
+            if r['status'] in set(['OVER_QUERY_LIMIT','OVER_DAILY_LIMIT']):
+                self.over_limit = True
+            return r
+        else:
+            return {'status':'OVER_QUERY_LIMIT','results':[]}
+
+    def distance(self,origins,destinations,mode='all',departure_time=None,arrival_time=None,transit_mode='subway|bus'):
+        '''
+        Uses Google API to find travel times betweel all originas and destinations.
+
+        Returns
+        -------
+        origins : list
+            List of lat,lon coordinates
+        destinations : list
+            List of lat,lon coordinates
+        mode : str (default='all')
+            Choose form driving, walking, transit
+        '''
+        if len(origins)*len(destinations)>100:
+            raise NameError('Number of elements per request exceeds limit:',len(origins)*len(destinations))
+        if len(origins[0])>2:
+            origins = [o[-2:] for o in origins]
+            destinations = [d[-2:] for d in destinations]
+
+        query = {'key':self.GOOGLE_GEOCODING_API_KEY,
+        'origins':'|'.join(map(lambda x: ','.join(map(str,x)),origins)),
+        'destinations':'|'.join(map(lambda x: ','.join(map(str,x)),destinations)),
+        'arrival_time':arrival_time,'departure_time':departure_time,
+        'transit_mode':transit_mode,'mode':mode}
+
+        if mode == 'all':
+            out = {'status':'all_modes'}
+            for m in ['driving','walking','transit']:
+                query['mode']=m
+                r = self._get(self.distance_base_url,params=query)
+                out[m] = r
+        else:
+            r = self._get(self.distance_base_url,params=query)
+            out = {mode:r}
+        return out
+
+    def _getWrapper(self,url,params):
+        if self.qCount>self.qLimit:
+            raise NameError('Local query limit exceeded')
+        r = requests.get(url,params=params).json()
+        self.qCount+=1
+        return r
+
+    def _get(self,url,params={}):
+        if not self.debug:
+            while (time.time()-self.time)<60./self.QPS:
+                time.sleep(1)
+            self.time = time.time()
+            # r = requests.get(url,params=params).json()
+            r = self._getWrapper(url,params)
+            while r['status']=='OVER_QUERY_LIMIT':
+                print('OVER_QUERY_LIMIT')
+                time.sleep(1)
+                # r = requests.get(url,params=params).json()
+                r = self._getWrapper(url,params)
+            while r['status']=='OVER_DAILY_LIMIT':
+                print('OVER_DAILY_LIMIT')
+                time.sleep(3600)
+                # r = requests.get(url,params=params).json()
+                r = self._getWrapper(url,params)
+        else:
+            r = {'status':'OK','results':[]}
+        return r