使用Python访问网络数据 python network-data 第六章(2)，,Welcome 吴铭

使用Python访问网络数据 python network-data 第六章(2)，,Welcome 吴铭

Welcome 吴铭英 from Using Python to Access Web Data

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Calling a JSON API

In this assignment you will write a Python program somewhat similar to http://www.pythonlearn.com/code/geojson.py. The program will prompt for a location, contact a web service and retrieve JSON for the web service and parse that data, and retrieve the first place_id from the JSON. A place ID is a textual identifier that uniquely identifies a place as within Google Maps.

API End Points

To complete this assignment, you should use this API endpoint that has a static subset of the Google Data:

http://python-data.dr-chuck.net/geojson

This API uses the same parameters (sensor and address) as the Google API. This API also has no rate limit so you can test as often as you like. If you visit the URL with no parameters, you get a list of all of the address values which can be used with this API.

To call the API, you need to provide a sensor=false parameter and the address that you are requesting as the address= parameter that is properly URL encoded using the urllib.urlencode() fuction as shown in http://www.pythonlearn.com/code/geojson.py

Test Data / Sample Execution

You can test to see if your program is working with a location of "South Federal University" which will have a place_id of "ChIJJ8oO7_B_bIcR2AlhC8nKlok".

$ python solution.pyEnter location: South Federal University Retrieving http://...Retrieved 2101 charactersPlace id ChIJJ8oO7_B_bIcR2AlhC8nKlok 

Turn In

Please run your program to find the place_id for this location:

Belorussian State University

Make sure to enter the name and case exactly as above and enter the place_id and your Python code below. Hint: The first seven characters of the place_id are "ChIJs3V ..."

Make sure to retreive the data from the URL specified above and not the normal Google API. Your program should work with the Google API - but the place_id may not match for this assignment.

Python code:

 1 import urllib 2 import json 3  4 serviceurl = ‘http://python-data.dr-chuck.net/geojson?‘ 5  6 while True: 7     address = raw_input(‘Enter location: ‘) 8     url = serviceurl + urllib.urlencode({‘sensor‘: ‘false‘, ‘address‘: address}) 9     print ‘Retrieving‘, url10     uh = urllib.urlopen(url)11     data = uh.read()12     print ‘Retrieved‘,len(data),‘characters‘13     input = urllib.urlopen(url).read()14     js = json.loads(input)15     print ‘Place id‘, js[‘results‘][0][‘place_id‘]

使用Python访问网络数据 python network-data 第六章(2)