Python File Handling: The Complete Beginner's Guide

file = open("example.txt", "r")
content = file.read()
file.close()

with open("example.txt", "r") as file:
    content = file.read()

with open("poem.txt", "r") as file:
    content = file.read()

with open("data.txt", "r") as file:
    first_line = file.readline()

with open("students.txt", "r") as file:
    lines = file.readlines()

with open("students.txt", "r") as file:
    for line in file:
        print(line.strip())

with open("output.txt", "w") as file:
    file.write("First line\n")
    file.write("Second line\n")

with open("log.txt", "a") as file:
    file.write("New log entry\n")

import csv

with open("students.csv", "r", newline="") as file:
    reader = csv.DictReader(file)
    for row in reader:
        print(row["name"], row["score"])

import csv

rows = [{"name": "Alice", "score": 88}, {"name": "Bob", "score": 75}]
with open("output.csv", "w", newline="") as file:
    writer = csv.DictWriter(file, fieldnames=["name", "score"])
    writer.writeheader()
    writer.writerows(rows)

import json

data = {"course": "Python", "students": [{"name": "Alice", "score": 88}]}
with open("course_data.json", "w") as file:
    json.dump(data, file, indent=2)

with open("course_data.json", "r") as file:
    loaded = json.load(file)

from pathlib import Path

path = Path("data") / "processed" / "output.csv"
print(path.exists())

from pathlib import Path
p = Path("notes.txt")
p.write_text("Hello\n")
print(p.read_text())

try:
    with open("missing.txt", "r") as file:
        content = file.read()
except FileNotFoundError:
    print("File not found")
except PermissionError:
    print("Permission denied")
except IsADirectoryError:
    print("Path is a directory")

with open("original.jpg", "rb") as source:
    image_data = source.read()

with open("copy.jpg", "wb") as dest:
    dest.write(image_data)

import csv
import json
from datetime import datetime

def read_student_scores(filepath):
    students = []
    with open(filepath, "r", newline="") as file:
        reader = csv.DictReader(file)
        for row in reader:
            students.append({
                "name": row["name"].strip(),
                "scores": [int(x) for x in row["scores"].split("|")],
                "course": row.get("course", "General"),
            })
    return students

def analyse_students(students):
    results = []
    for s in students:
        avg = sum(s["scores"]) / len(s["scores"])
        grade = "A" if avg >= 90 else "B" if avg >= 80 else "C" if avg >= 70 else "D" if avg >= 60 else "F"
        results.append({
            "name": s["name"],
            "course": s["course"],
            "average": round(avg, 1),
            "grade": grade,
            "passed": avg >= 60,
        })
    return sorted(results, key=lambda x: x["average"], reverse=True)