codesnips

preprocessing

python 
import cv2

image = cv2.imread('receipt.jpg')
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
blurred = cv2.GaussianBlur(gray, (5, 5), 0)
thresholded = cv2.adaptiveThreshold(

OpenCV image preprocessing for OCR and vision pipelines

opencv image-processing computer-vision
by Dr. Elena Vasquez 1 tab
python 
import pandas as pd

df = pd.read_csv('customers.csv')

df.columns = df.columns.str.strip().str.lower().str.replace(' ', '_', regex=False)

Cleaning missing values and normalizing messy CSV exports

pandas data-cleaning missing-values
by Dr. Elena Vasquez 1 tab
python 
import pandas as pd
from sklearn.compose import ColumnTransformer
from sklearn.impute import SimpleImputer
from sklearn.pipeline import Pipeline
from sklearn.preprocessing import OneHotEncoder, StandardScaler

Encoding categorical variables without creating leakage

categorical-encoding preprocessing scikit-learn
by Dr. Elena Vasquez 1 tab
python 
from sklearn.compose import ColumnTransformer
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.impute import SimpleImputer
from sklearn.pipeline import Pipeline
from sklearn.preprocessing import OneHotEncoder, StandardScaler
from sklearn.ensemble import RandomForestClassifier

ColumnTransformer pipelines that keep preprocessing honest

scikit-learn pipelines columntransformer
by Dr. Elena Vasquez 1 tab