Cheuk Ting Ho
Developer advocate / Data Scientist - support open-source and building the community.
How to be Pythonic? Design a Query Language in Python
Cheuk Ting Ho
Pythonic means code that doesn't just get the syntax right but that follows the conventions of the Python community and uses the language in the way it is intended to be used.
- Stackoverflow
🐼
Why can't I just do it in a for-loop?
for i in (i; i < items.length ; i++)
{
n = items[i];
... now do something
}for i in items:
i.perform_action()(i.some_attribute for i in items)🐍
Pythonic!
It all started...
Co-organizer of
Open Source contribution
Creator of
Volenteer of
Developer Advocate of
SELECT Name from TABLE where Person_ID = (SELECT mother from TABLE where Name="John")
SELECT Name from TABLE where Person_ID = (SELECT mother from TABLE WHERE Person_ID = (SELECT mother from TABLE where Name="John"))WOQL.and(
WOQL.triple("v:Person", "mother", "v:MotherID"),
WOQL.triple("v:MotherID", "name", "v:MotherName"),
WOQL.triple("v:MotherID", "mother", "v:GrandmotherID"),
WOQL.triple("v:GrandmotherID", "name", "v:GrandmotherName"),
)a Query Language Client for Pythonistas and Data Scientists
WOQLpy
🤔
💡
👏👏👏👏👏👏👏👏
What is WOQLpy?
It comes with the Python Client, which you can pip install:
pip install terminusdb-clientOutput to DataFrames
pip install terminusdb-client[dataframe]WOQLDataFrame.result_to_df(result)Change the result returned form your query into pandas DataFrame
🐼
It let's you to "talk" to TerminusDB like this:
import terminusdb_client as woql
from terminusdb_client import WOQLQuery
db_id = "pybike"
client = woql.WOQLClient(server_url = "http://localhost:6363")
client.connect(key="root", account="admin", user="admin")
client.create_database(db_id, accountid="admin", label = "Bike Graph",
description = "Create a graph with bike data")
station_dt = WOQLQuery().doctype("Station",
label="Bike Station",
description="A station where bikes are deposited")
bicycle_dt = WOQLQuery().doctype("Bicycle", label="Bicycle")
journey_dt = (
WOQLQuery().doctype("Journey", label="Journey").
property("start_station", "Station", label="Start Station").
property("end_station", "Station", label="End Station").
property("duration", "integer", label="Journey Duration").
property("start_time", "dateTime", label="Time Started").
property("end_time", "dateTime", label="Time Ended").
property("journey_bicycle", "Bicycle", label="Bicycle Used")
)
schema = station_dt + bicycle_dt + journey_dt
schema.execute(client)Instead of this:
{
"when": [
{
"true": []
},
{
"and": [
{
"add_quad": [
"scm:Station",
"rdf:type",
"owl:Class",
"db:schema"
]
},
{
"add_quad": [
"scm:Station",
"rdfs:subClassOf",
"tcs:Document",
"db:schema"
]
},
{
"add_quad": [
"scm:Station",
"rdfs:label",
{
"@value": "Bike Station",
"@language": "en"
},
"db:schema"
]
},
{
"add_quad": [
"scm:end_station",
"rdf:type",
"owl:ObjectProperty",
"db:schema"
]
},
{
"add_quad": [
"scm:end_station",
"rdfs:range",
"scm:Station",
"db:schema"
]
},
{
"add_quad": [
"scm:end_station",
"rdfs:domain",
"scm:Journey",
"db:schema"
]
},
{
"and": [
{
"add_quad": [
"scm:start_station",
"rdf:type",
"owl:ObjectProperty",
"db:schema"
]
},
{
"add_quad": [
"scm:start_station",
"rdfs:range",
"scm:Station",
"db:schema"
]
},
{
"add_quad": [
"scm:start_station",
"rdfs:domain",
"scm:Journey",
"db:schema"
]
},
{
"and": [
{
"add_quad": [
"scm:Journey",
"rdf:type",
"owl:Class",
"db:schema"
]
},
{
"add_quad": [
"scm:Journey",
"rdfs:subClassOf",
"tcs:Document",
"db:schema"
]
},
{
"add_quad": [
"scm:Journey",
"rdfs:label",
{
"@value": "Journey",
"@language": "en"
},
"db:schema"
]
}
]
},
{
"add_quad": [
"scm:start_station",
"rdfs:label",
{
"@value": "Start Station",
"@language": "en"
},
"db:schema"
]
}
]
},
{
"add_quad": [
"scm:end_station",
"rdfs:label",
{
"@value": "End Station",
"@language": "en"
},
"db:schema"
]
}
]
}
]
}You can do both
(WOQLQuery().doctype("Station")
.label("Bike Station")
.description("A station where bikes are deposited")
)or
WOQLQuery().doctype("Station",
label="Bike Station",
escription="A station where bikes are deposited")Design challanges
JavaScript: WOQL.and()
Python: WOQLQuery().and() ?
"and" is a key word, you dummy!
OK, woql_and then....😓
WOQLQuery().woql_and()
* actually you can use the + operator thanks for the overload ability in Python
also happened to: or, not, as, from...
Integration with Jupyter notebook
Schema builder
class Coordinate(Object):
x : float
y : float
class Country(Document):
name : str
perimeter : List[Coordinate]
class Address(Object):
street : str
country : Country
class Person(Document):
name : str
age : int
friend_of : Set['Person']
class Employee(Person):
address_of : Address
contact_number : str
managed_by : 'Employee'Look into the future
Mass loading data from DataFrame (and csvs)
🐼
Schema checker
Network graph analysing algorithms
**Your suggestion here**
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https://academy.terminusdb.com/
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Conf42 - How to be Pythonic? Design a Query Language in Python
By Cheuk Ting Ho
