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pycarol 2.55.3

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For the latest source, discussion, etc, please visit the
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PyCarol

Contents

PyCarol

Getting Started
Initializing pyCarol
Using API Key
Good practice using token
Ingesting data

From both Staging Tables and Data Models (BQ Layer)
From Data Models (RT Layer): Filter queries
From Data Models (RT Layer): Named queries

Sending data
Logging
Settings
Useful Functions
Release process

Getting Started
Run pip install pycarol to install the latest stable version from PyPI. Documentation for the latest release is hosted on readthedocs.
This will install the minimal dependencies. To install pyCarol with the dataframes dependencies use
pip install pycarol[dataframe], or to install with dask+pipeline dependencies use pip install pycarol[pipeline,dask]
The options we have are: complete, dataframe, onlineapp, dask, pipeline
To install from source:

pip install -r requirements.txt to install the minimal requirements;
pip install -e . ".[dev]" to install the minimal requirements + dev libs;
pip install -e . ".[pipeline]" to install the minimal requirements + pipelines dependencies;
pip install -e . ".[complete]" to install all dependencies;

Initializing pyCarol
Carol is the main object to access pyCarol and all Carol’s APIs.
from pycarol import PwdAuth, Carol
carol = Carol(domain=TENANT_NAME, app_name=APP_NAME,
auth=PwdAuth(USERNAME, PASSWORD), organization=ORGANIZATION)
where domain is the tenant name, app_name is the Carol’s app name, if any, auth
is the authentication method to be used (using user/password in this case) and organization is the organization
one wants to connect. Carols’s URL is build as www.ORGANIZATION.carol.ai/TENANT_NAME
It is also possible to initialize the object with a token generated via user/password. This is useful when creating an
online app that interacts with Carol
from pycarol import PwdKeyAuth, Carol
carol = Carol(domain=TENANT_NAME, app_name=APP_NAME,
auth=PwdKeyAuth(pwd_auth_token), organization=ORGANIZATION)

Using API Key
To use API keys instead of username and password:
from pycarol import ApiKeyAuth, Carol

carol = Carol(domain=DOMAIN,
app_name=APP_NAME,
auth=ApiKeyAuth(api_key=X_AUTH_KEY),
connector_id=CONNECTOR, organization=ORGANIZATION)
In this case one changes the authentication method to ApiKeyAuth. Noticed that one needs to pass the connector_id
too. An API key is always associated to a connector ID.
It is possible to use pyCarol to generate an API key
from pycarol import PwdAuth, ApiKeyAuth, Carol

carol = Carol(domain=TENANT_NAME, app_name=APP_NAME, organization=ORGANIZATION,
auth=PwdAuth(USERNAME, PASSWORD), connector_id=CONNECTOR)
api_key = carol.issue_api_key()

print(f"This is a API key {api_key['X-Auth-Key']}")
print(f"This is the connector Id {api_key['X-Auth-ConnectorId']}")
To get the details of the API key you can do:
details = carol.api_key_details(APIKEY, CONNECTORID)
Finally, to revoke an API key:
carol.api_key_revoke(CONNECTORID)

Good practice using token
Never write in plain text your password/API token in your application. Use environment variables. pyCarol can use
environment variables automatically. When none parameter is passed to the Carol constructor pycarol will look for:

CAROLTENANT for domain
CAROLAPPNAME for app_name
CAROL_DOMAIN for environment
CAROLORGANIZATION for organization
CAROLAPPOAUTH for auth
CAROLCONNECTORID for connector_id
CAROLUSER for carol user email
CAROLPWD for user password.

e.g., one can create a .env file like this:

CAROLAPPNAME=myApp
CAROLTENANT=myTenant
CAROLORGANIZATION=myOrganization
CAROLAPPOAUTH=myAPIKey
CAROLCONNECTORID=myConnector
and then
from pycarol import Carol
from dotenv import load_dotenv
load_dotenv(".env") #this will import these env variables to your execution.
carol = Carol()

Ingesting data

From both Staging Tables and Data Models (BQ Layer)
Use this method when you need to read only a subset of records and columns or when
data transformation is needed.
from pycarol import BQ, Carol

bq = BQ(Carol())
query_str = "SELECT * FROM stg_connectorname_table_name"
results = bq.query(query_str)
In case one needs a service account with access to BigQuery, the following code can be
used:
from pycarol import Carol
from pycarol.bigquery import TokenManager

tm = TokenManager(Carol())
service_account = tm.get_token().service_account
After each execution of BQ.query, the BQ object will have an attribute called
job. This attribute is of type bigquery.job.query.QueryJob and may be useful for
monitoring/debug jobs.
PyCarol provides access to BigQuery Storage API also. It allows for much faster reading
times, but with limited querying capabilities. For instance, only tables are readable,
so ‘ingestion_stg_model_deep_audit’ is ok, but ‘stg_model_deep_audit’ is not (it is a
view).
from pycarol import BQStorage, Carol

bq = BQStorage(Carol())
table_name = "ingestion_stg_model_deep_audit"
col_names = ["request_id", "version"]
restriction = "branch = '01'"
sample_size = 1000
df = bq.query(
table_name,
col_names,
row_restriction=restriction,
sample_percentage=sample_size,
return_dataframe=True
)

From Data Models (RT Layer): Filter queries
Use this when you need low latency (only if RT layer is enabled).
from pycarol.filter import TYPE_FILTER, TERM_FILTER, Filter
from pycarol import Query
json_query = Filter.Builder() \
.must(TYPE_FILTER(value='ratings' + "Golden")) \
.must(TERM_FILTER(key='mdmGoldenFieldAndValues.userid.raw',value='123'))\
.build().to_json()

FIELDS_ITEMS = ['mdmGoldenFieldAndValues.mdmaddress.coordinates']
query = Query(carol, page_size=10, print_status=True, only_hits=True,
fields=FIELDS_ITEMS, max_hits=200).query(json_query).go()
query.results
The result will be 200 hits of the query json_query above, the pagination will be 10, that means in each response
there will be 10 records. The query will return only the fields set in FIELDS_ITEMS.
The parameter only_hits = True will make sure that only records into the path $hits.mdmGoldenFieldAndValues will return.
If one wants all the response use only_hits = False. Also, if your filter has an aggregation, one should use
only_hits = False and get_aggs=True, e.g.,
from pycarol import Query
from pycarol.filter import TYPE_FILTER, Filter, CARDINALITY

json_query = Filter.Builder() \
.must(TYPE_FILTER(value='datamodelname' + "Golden")) \
.aggregation(CARDINALITY(name='cardinality', params = ["mdmGoldenFieldAndValues.taxid.raw"], size=40))\
.build().to_json()

query = Query(carol, get_aggs=True, only_hits=False)
query.query(json_query).go()
query.results

From Data Models (RT Layer): Named queries
from pycarol import Query

named_query = 'revenueHist' # named query name
params = {"bin":"1d","cnpj":"24386434000130"} #query parameters to send.
results = Query(carol).named(named_query, params=params).go().results
It is possible to use all the parameters used in the filter query, i.e., only_hits ,
save_results, etc. For more information for the possible input parameters check the docstring.
What if one does not remember the parameters for a given named query?
named_query = 'revenueHist' # named query name
Query(carol).named_query_params(named_query)
> {'revenueHist': ['*cnpj', 'dateFrom', 'dateTo', '*bin']} #Parameters starting by * are mandatory.

Sending data
The first step to send data to Carol is to create a connector.
from pycarol import Connectors
connector_id = Connectors(carol).create(name='my_connector', label="connector_label", group_name="GroupName")
print(f"This is the connector id: {connector_id}")
With the connector Id on hands we can create the staging schema and then create the staging table. Assuming we have
a sample of the data we want to send.
from pycarol import Staging

json_ex = {"name":'Rafael',"email": {"type": "email", "email": 'rafael@totvs.com.br'} }

staging = Staging(carol)
staging.create_schema(staging_name='my_stag', data = json_ex,
crosswalk_name= 'my_crosswalk' ,crosswalk_list=['name'],
connector_name='my_connector')
The json schema will be in the variable schema.schema. The code above will create the following schema:
{
'mdmCrosswalkTemplate': {
'mdmCrossreference': {
'my_crosswalk': [
'name'
]
}
},
'mdmFlexible': 'false',
'mdmStagingMapping': {
'properties': {
'email': {
'properties': {
'email': {
'type': 'string'
},
'type': {
'type': 'string'
}
},
'type': 'nested'
},
'name': {
'type': 'string'
}
}
},
'mdmStagingType': 'my_stag'
}
To send the data (assuming we have a json with the data we want to send).
from pycarol import Staging

json_ex = [{"name":'Rafael',"email": {"type": "email", "email": 'rafael@totvs.com.br'} },
{"name":'Leandro',"email": {"type": "email", "email": 'Leandro@totvs.com.br'} },
{"name":'Joao',"email": {"type": "email", "email": 'joao@rolima.com.br'} },
{"name":'Marcelo',"email": {"type": "email", "email": 'marcelo@totvs.com.br'} }]

staging = Staging(carol)
staging.send_data(staging_name = 'my_stag', data = json_ex, step_size = 2,
connector_id=connectorId, print_stats = True)
The parameter step_size says how many registers will be sent each time. Remember the the max size per payload is
5MB. The parameter data can be a pandas DataFrame.
OBS: It is not possible to create a mapping using pycarol. The Mapping has to be done via the UI

Logging
To log messages to Carol:
from pycarol import Carol, CarolHandler
import logging

logger = logging.getLogger(__name__)
logger.setLevel(logging.DEBUG)
carol = CarolHandler(Carol())
carol.setLevel(logging.INFO)
logger.addHandler(carol)

logger.debug('This is a debug message') #This will not be logged in Carol. Level is set to INFO
logger.info('This is an info message')
logger.warning('This is a warning message')
logger.error('This is an error message')
logger.critical('This is a critical message')
These methods will use the current long task id provided by Carol when running your application.
For local environments you need to set that manually first on the beginning of your code:
import os
os.environ['LONGTASKID'] = task_id
We recommend to log only INFO+ information in Carol. If no TASK ID is passed it works as a Console Handler.

Settings
We can use pyCarol to access the settings of your Carol App.
from pycarol.apps import Apps
app = Apps(carol)
settings = app.get_settings(app_name='my_app')
print(settings)
The settings will be returned as a dictionary where the keys are the parameter names and the values are
the value for that parameter. Please note that your app must be created in Carol.

Useful Functions

track_tasks: Track a list of tasks.

from pycarol import Carol
from pycarol.functions import track_tasks
carol = Carol()
def callback(task_list):
print(task_list)
track_tasks(carol=carol, task_list=['task_id_1', 'task_id_2'], callback=callback)

Release process

Open a PR with your change for master branch;
Once approved, merge into master;
In case there are any changes to the default release notes, please update them