File Handling and I/O

Which mode opens file for writing?

Which mode appends to existing file?

What does read() return?

Which reads all lines into list?

What is the with statement for?

Which module handles CSV files?

What does json.dumps() do?

Which method writes string to file?

What does 'rb' mode mean?

Which checks if file exists?

Explain file modes: r, w, a, x, b, + with examples.

What is the advantage of using with statement for files?

Explain seek() and tell() methods for file positioning.

What is the difference between readline() and readlines()?

Explain CSV module: reader vs DictReader, writer vs DictWriter.

What are JSON and pickle modules? Compare their use cases.

Explain file encoding and why UTF-8 is recommended.

How to handle large files that don't fit in memory?

Explain os and shutil modules for file operations.

What is file buffering and flush() method?

Write a program to count lines, words, and characters in a file.

Create a program to copy one file to another (binary mode).

Write a CSV reader that calculates average of numeric columns.

Create a JSON converter that transforms CSV to JSON format.

Write a log file analyzer that counts ERROR vs WARNING entries.

Create a configuration file parser (simple key=value format).

Find error: f = open('data.txt') f.write('Hello') f.close()

Predict behavior: with open('test.txt', 'w') as f: f.write('Line 1') f.write('Line 2') print(f.closed)

Find error: f = open('data.txt', 'r') print(f.read()) print(f.read()) f.close()

Predict output: import json data = {'a': 1, 'b': [2, 3]} print(json.dumps(data, indent=2))

Find error: import csv with open('data.csv', 'r') as f: reader = csv.reader(f) for row in reader: print(row[5])

Predict behavior: f = open('test.txt', 'w') f.write('Hello') # Forgot to close print('Done')

Find error: with open('data.txt', 'rb') as f: content = f.read() print(content.upper())

Predict output: with open('test.txt', 'w') as f: print('Hello', 'World', sep='-', file=f) # File now contains