Python Programming Labs

Your Task: Learn to serialize and deserialize data using Python's json module for data interchange.

Detailed Requirements:
1. Basic JSON operations:
import json # Python dict to JSON string data = {"name": "Alice", "age": 30, "active": True} json_string = json.dumps(data) print(json_string) # '{"name": "Alice", "age": 30, "active": true}' # JSON string to Python dict parsed = json.loads(json_string) print(parsed["name"]) # Alice

2. Pretty printing and formatting:
# Pretty print with indentation data = {"users": [{"name": "Alice"}, {"name": "Bob"}]} pretty = json.dumps(data, indent=2, sort_keys=True) print(pretty) # Custom separators compact = json.dumps(data, separators=(',', ':')) print(compact) # No extra spaces

3. File operations:
# Write JSON to file with open('data.json', 'w') as f: json.dump(data, f, indent=2) # Read JSON from file with open('data.json', 'r') as f: loaded = json.load(f) print(loaded)

4. Custom serialization:
from datetime import datetime class DateEncoder(json.JSONEncoder): def default(self, obj): if isinstance(obj, datetime): return obj.isoformat() return super().default(obj) data = {"timestamp": datetime.now()} json_str = json.dumps(data, cls=DateEncoder) print(json_str) # {"timestamp": "2024-01-15T10:30:00"}

💡 Pro Tips:
• dumps/loads work with strings
• dump/load work with files
• Use indent for human-readable output
• Custom encoder for non-JSON types

Expected Output:
JSON: {"name": "Alice", "age": 30} Parsed: {'name': 'Alice', 'age': 30} Pretty printed JSON with indentation

Your Task: Master the pathlib module for modern, object-oriented file path handling.

Detailed Requirements:
1. Creating and using paths:
from pathlib import Path # Create path objects home = Path.home() current = Path.cwd() file_path = Path('/usr/local/bin/python') # Path from string p = Path('folder/subfolder/file.txt') print(p) # folder/subfolder/file.txt

2. Path components:
p = Path('/home/user/documents/report.pdf') print(p.name) # report.pdf print(p.stem) # report print(p.suffix) # .pdf print(p.parent) # /home/user/documents print(p.parts) # ('/', 'home', 'user', 'documents', 'report.pdf') print(p.anchor) # /

3. Path operations:
# Joining paths (use / operator) base = Path('/home/user') full = base / 'documents' / 'file.txt' print(full) # /home/user/documents/file.txt # Changing extensions p = Path('data.csv') new_p = p.with_suffix('.json') print(new_p) # data.json # Changing filename p = Path('folder/old.txt') new_p = p.with_name('new.txt') print(new_p) # folder/new.txt

4. File system operations:
p = Path('myfile.txt') # Check existence print(p.exists()) # True/False print(p.is_file()) # True if file print(p.is_dir()) # True if directory # List directory contents folder = Path('.') for item in folder.iterdir(): print(item) # Glob patterns for py_file in folder.glob('*.py'): print(py_file) # Recursive glob for py_file in folder.rglob('**/*.py'): print(py_file)

💡 Pro Tips:
• Use / operator to join paths
• Path.cwd() for current directory
• Path.home() for home directory
• glob() and rglob() for pattern matching

Expected Output:
Path: /home/user/documents/file.txt Name: file.txt Stem: file Suffix: .txt

Your Task: Master the datetime module for working with dates, times, and time deltas.

Detailed Requirements:
1. Current date and time:
from datetime import datetime, date, time, timedelta # Current datetime now = datetime.now() print(now) # 2024-01-15 10:30:45.123456 # Current date only today = date.today() print(today) # 2024-01-15 # UTC time utc_now = datetime.utcnow() print(utc_now)

2. Creating specific dates/times:
# Create specific datetime dt = datetime(2024, 12, 25, 14, 30, 0) print(dt) # 2024-12-25 14:30:00 # Create date d = date(2024, 7, 4) print(d) # 2024-07-04 # Create time t = time(14, 30, 45) print(t) # 14:30:45

3. Formatting and parsing:
# Format datetime to string now = datetime.now() formatted = now.strftime('%Y-%m-%d %H:%M:%S') print(formatted) # 2024-01-15 10:30:45 # Common format codes: # %Y - Year (2024) %m - Month (01-12) # %d - Day (01-31) %H - Hour (00-23) # %M - Minute (00-59) %S - Second (00-59) # %A - Weekday name %B - Month name # Parse string to datetime date_str = '2024-12-25' parsed = datetime.strptime(date_str, '%Y-%m-%d') print(parsed) # 2024-12-25 00:00:00

4. Time arithmetic with timedelta:
# Create time deltas one_day = timedelta(days=1) one_week = timedelta(weeks=1) custom = timedelta(days=5, hours=3, minutes=30) # Add/subtract from dates now = datetime.now() tomorrow = now + one_day yesterday = now - one_day next_week = now + one_week print(f"Tomorrow: {tomorrow}") print(f"Yesterday: {yesterday}") # Difference between dates d1 = datetime(2024, 1, 1) d2 = datetime(2024, 12, 31) diff = d2 - d1 print(f"Days between: {diff.days}")

💡 Pro Tips:
• strftime = string from time (format)
• strptime = string parse time (parse)
• Use timedelta for date math
• date.today() for just the date

Expected Output:
Now: 2024-01-15 10:30:45 Formatted: January 15, 2024 Tomorrow: 2024-01-16 10:30:45