Hi,
Sorry for the late response. Thank you all for your valuable suggestions. I
used the urllib module of python to send the request to XAPI url giving
bounding box coordinates and read the response. When user runs the script,
it prompts the user to enter bbox coordinates and check whether those
entered coordinates in lat/long limits and build the URL like below.
http://www.informationfreeway.org/api/0.6/map?bbox=*x1,y1,x2,y2*
This is working fine. But is is downloading all the data for the given bbox
coordinates. If I want to download only selected elements then I need to
append filter predicates also to the URL.
It would be helpful for me if anyone suggests how to do this by giving GUI
for the script instead of prompting user to enter his selection in the
command prompt. If any automated tools available with user interface also
fine for me.
Thanks
Phanindra
On Fri, Nov 8, 2013 at 8:53 AM, amrit karmacharya amrit...@gmail.comwrote:
there is an existing library https://launchpad.net/osmxapi
On Fri, Nov 8, 2013 at 7:37 AM, Pierre Béland pierz...@yahoo.fr wrote:
Hi Phanindra,
This is a late answer but I took time to test the solution using the
urllib2 module to send a request to a website and extract data. I give you
an example with the Overpass API.
Using Overpass is a very interesting solution to extract for a bbox and
pass the result to Python. It is possible to output in json and then
convert easily to Python dictionary objects. The python script example
below uses the urllib2 module to send a request and read the result.
The url contains the instructions sent to the Overpass API. In this
example, The nodes that have a name Tag are extracted for the given bbox.
In the dictionary, elements contains the list of elements extracted from
OSM. The string function .decode('utf8') let's decode and print correctly
the UTF8 characters.
Pierre
Python script
---
import urllib2,urllib,json
# space replaced with + sign
url='
http://overpass.osm.rambler.ru/cgi/interpreter?data=[out:json];(node[name](45.37301118463942,-72.80742645263672,45.416286468478475,-72.71095275878906););out+body
;'
try:
print try request
overpass_response = urllib2.urlopen(url)
print info
print overpass_response.info()
#overpass_response = urllib2.urlopen(url_o)
except urllib2.HTTPError as e:
# list of error codes at http://docs.python.org/2/howto/urllib2.html
print('The server couldn\'t fulfill the request.')
print('Error code: ', e.code, responses[e.code])
print urllib2.info()
except urllib2.URLError as e:
print('We failed to reach a server.')
print('Reason: ', e.reason)
else:
# everything is fine
#overpass_response = open(overpass_request)
#print apres open
overpass_txt=overpass_response.read().decode('utf8')
overpass_response.close()
overpass_json = json.loads(overpass_txt)
print dictionnary elements - we access and print each element of the
list
elements=overpass_json[elements]
nb=0
for element in elements:
nb+=1
print \n,nb,\t,element
print \t+element[type]+, id=+str(element[id])+,
lat=+str(element[lat])+, lon=+str(element[lon])
if (name in element[tags]):
print \tname=+element[tags][name]
--
*De :* Phanindra Kuchipudi phani@gmail.com
*À :* dev@openstreetmap.org
*Envoyé le :* Lundi 4 novembre 2013 0h26
*Objet :* [OSM-dev] Downloading OSM data
Hi,
I want to write a python script to download OSM data based on a given
bounding box (implementing XAPI).
Can anyone help me how to develop this script, and also can you give
information on any other scripts available for this downloading
functionality?
Thanks,
Phani
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