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Custom step

Custom steps allow you to implement arbitrary python in your pipeline.

Custom steps require a function, called a transform as well as pydandic model that defines the output schema. Optionally you can provide a name.

The logic really can be arbitrary, including API calls, Langchain chains, local generative models or simple data cleaning.


This is an extremely simple custom step, implemented merely as a lambda function.

select_category_step = steps.CustomStep(
  transform=lambda row: row[f'category{row["category_index"]}'],

API call as a custom step

In this example we wrap an API call in a custom step. The result will be three new columns to our dataframe as defined by the pydantic model.

import json
from datetime import datetime
import requests
from pydantic import BaseModel, Field

api_key = 'API_KEY'

def get_linkedin_data(profile, api_key=api_key):

    headers = {'Authorization': 'Bearer ' + api_key}
    api_endpoint = ''
    params = {
        'linkedin_profile_url': '{profile}/',
        'extra': 'include',
        'github_profile_id': 'include',
        'facebook_profile_id': 'include',
        'twitter_profile_id': 'include',
        'personal_contact_number': 'include',
        'personal_email': 'include',
        'inferred_salary': 'include',
        'skills': 'include',
        'use_cache': 'if-present',
        'fallback_to_cache': 'on-error',
    response = requests.get(api_endpoint,

    # JSON string provided
    json_str = response.content

    # Load the JSON string into a Python dictionary
    profile = json.loads(json_str)

    # Extract occupation
    headline = profile.get('headline', 'Not provided')

    # Extract the most recent job
    experiences = profile.get('experiences', [])
    most_recent_job = experiences[0] if experiences else 'Not provided'

    # Calculate years of work experience since college
    education = profile.get('education', [])
    college_graduation_year = None
    for edu in education:
        if 'Bachelor' in edu.get('degree_name', ''):
            college_graduation_year = edu.get('ends_at', {}).get('year')

    years_of_experience = - college_graduation_year if college_graduation_year else 'Not provided'

    return({'headline': headline, 'most_recent_job': most_recent_job.get('title'), 'years_of_experience': years_of_experience})

linkedin_step = steps.CustomStep(