#!/usr/bin/env python
# coding: utf-8

# ## Basic SPARQLProg example
# 
# This basic example walks through querying the Wikidata SPARQL endpoint.
# 
# We make use of the wikidata module that is part of sparqlprog, and provides access to predicates such as `continent/1` (for instances of continents) and the generic `enlabel/2` (which maps an entity to it's English-language label)
# 

# In[1]:


from prologterms import TermGenerator, PrologRenderer, Program, Var
from sparqlprog import SPARQLProg
P = TermGenerator()


# In[2]:


server = 'http://localhost:9083'
# server = 'https://evening-falls-87315.herokuapp.com'


# In[3]:


S = SPARQLProg(server=server,
               endpoint='wd')


# ### setting up a query

# In[4]:


# our query will join over two predicates
C = Var('C')
N = Var('N')
query = (P.continent(C), P.enlabel(C, N)) # same as logic program query: continent(C), enlabel(C,N)


# ### running the query
# 

# In[5]:


res = S.query(query)

for r in res:
    print(f"{r.C} {r.N}")


# In[6]:


C = Var('C')
D = Var('D')
CN = Var('CN')
DN = Var('DN')

query = (
     P.country(D),
     P.part_of_continent(D,C),
     P.continent(C),
     P.enlabel(D,DN),
     P.enlabel(C,CN)
    )

res = S.query(query)
for r in list(res)[0:8]:
    print(f"{r.D} {r.DN} part-of {r.C} {r.CN}")


# In[7]:


df = S.query_to_dataframe(query)


# In[8]:


df


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