Obtain the query interface url of BCS server.

[DFS]

On 9/13/2022 3:46 AM, hongy... at gmail.com wrote:
> On Tuesday, September 13, 2022 at 4:20:12 AM UTC+8, DFS wrote:
>> On 9/12/2022 5:00 AM, hongy... at gmail.com wrote:
>>> I want to do the query from with in script based on the interface here [1]. For this purpose, the underlying posting URL must be obtained, say, the URL corresponding to "ITA Settings" button, so that I can make the corresponding query URL and issue the query from the script.
>>>
>>> However, I did not find the conversion rules from these buttons to the corresponding URL. Any hints for achieving this aim?
>>>
>>> [1] https://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-getgen?list=new&what=gen&gnum=10
>>>
>>> Regards,
>>> Zhao
>> You didn't say what you want to query. Are you trying to download
>> entire sections of the Bilbao Crystallographic Server?
> 
> I am engaged in some related research and need some specific data used by BCS server.

What specific data?

Is it available elsewhere?


>> Maybe the admins will give you access to the data.
> 
> I don't think they will provide such convenience to researchers who have no cooperative relationship with them.

You can try.  Tell the admins what data you want, and ask them for the 
easiest way to get it.


>> * this link: https://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-getgen
>> brings up the table of space group symbols.
>>
>> * choose say #7: Pc
>>
>> * now click ITA Settings, then choose the last entry "P c 1 1" and it
>> loads:
>>
>> https://www.cryst.ehu.es/cgi-bin/cryst/programs//nph-trgen?gnum=007&what=gp&trmat=b,-a-c,c&unconv=P%20c%201%201&from=ita
> 
> Not only that, but I want to obtain all such URLs programmatically!
>   
>> You might be able to fool around with that URL and substitute values and
>> get back the data you want (in HTML) via Python. Do you really want
>> HTML results?
>>
>> Hit Ctrl+U to see the source HTML of a webpage
>>
>> Right-click or hit Ctrl + Shift + C to inspect the individual elements
>> of the page
> 
> For batch operations, all these manual methods are inefficient.

Yes, but I don't think you'll be able to retrieve the URLs 
programmatically.  The JavaScript code doesn't put them in the HTML 
result, except for that one I showed you, which seems like a mistake on 
their part.

So you'll have to figure out the search fields, and your python program 
will have to cycle through the search values:

Sample from above
gnum   = 007
what   = gp
trmat  = b,-a-c,c
unconv = P c 1 1
from   = ita

wBase   = "https://www.cryst.ehu.es/cgi-bin/cryst/programs//nph-trgen"
wGnum   = "?gnum="   + findgnum
wWhat   = "&what="   + findWhat
wTrmat  = "&trmat="  + findTrmat
wUnconv = "&unconv=" + findUnconv
wFrom   = "&from="   + findFrom
webpage  = wBase + wGnum + wWhat + wTrmat + wUnconv + wFrom

Then if that returns a hit, you'll have to parse the resulting HTML and 
extract the exact data you want.



I did something similar a while back using the requests and lxml libraries
----------------------------------------------------------------
#build url
wBase    = "http://www.usdirectory.com"
wForm    = "/ypr.aspx?fromform=qsearch"
wKeyw    = "&qhqn=" + keyw
wCityZip = "&qc="   + cityzip
wState   = "&qs="   + state
wDist    = "&rg="   + str(miles)
wSort    = "&sb=a2z"  #sort alpha
wPage    = "&ap="   #used with the results page number
webpage  = wBase + wForm + wKeyw + wCityZip + wState + wDist

#open URL
page     = requests.get(webpage)
tree     = html.fromstring(page.content)

#no matches
matches = tree.xpath('//strong/text()')
if passNbr == 1 and ("No results were found" in str(matches)):
	print "No results found for that search"
	exit(0)
----------------------------------------------------------------



2.x code file: https://file.io/VdptORSKh5CN



> Best Regards,
> Zhao