Reference library

Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

4 matches
Files & data easy

Automatically Highlight Data Validation Errors Inside Excel Files in Python

Load an Excel file with openpyxl, iterate over cells, and highlight invalid data (empty, negative) with a red fill and error message.

excel validation openpyxl
Python 
import openpyxl
from openpyxl.styles import PatternFill
from pathlib import Path

def highlight_validation_errors(filepath: str, output_path: str = None):
    wb = openpyxl.load_workbook(filepath)
    red_fill = PatternFill(start_color="FF0000", end_color="FF0000", fill_type="solid")
    
    for sheet in wb.worksheet…
60 0 Open
Data pipelines & processing medium

How to Validate Fact Table Grain Row Counts in Python

Validate fact table grain by checking dimension key references, unique grain combinations, duplicate rows, and dimension cardinality from a CSV file.

csv data validation etl
Python 
import csv
import hashlib
from pathlib import Path


def validate_fact_grain(fact_file: Path, expected_dim_keys: dict[str, set[str]]) -> dict:
    """
    Validate fact table grain by checking each row's dimension keys exist
    in expected dimension tables and row count consistency.
    """
    dim_references = {}
  …
13 0 Open
Testing & modern typing medium

How to Use TypedDict for Data Validation in Python

Define a TypedDict schema and validate raw dictionary input with type hints for safer, more readable data handling.

typeddict typing validation
Python 
from typing import Any, Dict, List, Optional, Union, TypedDict, Literal

class Product(TypedDict):
    product_id: int
    name: str
    price: Union[int, float]
    in_stock: bool
    tags: Optional[List[str]]

def validate_product(data: Dict[str, Any]) -> Product:
    product_id: int = int(data["product_id"])
    na…
14 0 Open
ML engineering pipelines easy

How to Build a Data Validation Schema in Python

Create a lightweight validation schema using dataclasses and lambda validators to check fields in a dictionary.

validation dataclasses ml-pipelines
Python 
import re
from dataclasses import dataclass, field
from typing import Any, Callable


@dataclass
class Field:
    name: str
    validator: Callable[[Any], bool]
    required: bool = True

    def validate(self, value: Any) -> bool:
        if not self.required and value is None:
            return True
        return …
12 0 Open

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Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.

Related coding tools

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