POST REQUESTS - Sending data with urllib

#!/usr/bin/env python3
"""
POST REQUESTS - Sending data with urllib
Demonstrates HTTP POST with form data
"""

import urllib.request
import urllib.parse

print("=" * 60)
print("POST REQUESTS - Sending Data")
print("=" * 60)

# Example 1: Basic POST request
print("\n1. Basic POST Request")
print("-" * 40)
url = "http://httpbin.org/post"
data = {'name': 'John', 'age': '30'}
encoded_data = urllib.parse.urlencode(data).encode('utf-8')

try:
    request = urllib.request.Request(url, data=encoded_data)
    with urllib.request.urlopen(request) as response:
        print(f"  Status: {response.status}")
        print(f"  Method: POST")
        result = response.read().decode('utf-8')
        print(f"  Response length: {len(result)} bytes")
except Exception as e:
    print(f"  Error: {e}")

# Example 2: POST with multiple fields
print("\n2. POST with Multiple Fields")
print("-" * 40)
form_data = {
    'username': 'alice',
    'password': 'secret123',
    'email': 'alice@example.com'
}
encoded = urllib.parse.urlencode(form_data).encode('utf-8')

try:
    req = urllib.request.Request(url, data=encoded, method='POST')
    with urllib.request.urlopen(req) as response:
        print(f"  Posted {len(form_data)} fields")
        print(f"  Status: {response.status}")
except Exception as e:
    print(f"  Error: {e}")

# Example 3: POST JSON data
print("\n3. POST JSON Data")
print("-" * 40)
import json

json_data = {'key': 'value', 'number': 42}
json_bytes = json.dumps(json_data).encode('utf-8')

try:
    req = urllib.request.Request(url, data=json_bytes)
    req.add_header('Content-Type', 'application/json')
    with urllib.request.urlopen(req) as response:
        print(f"  Posted JSON data")
        print(f"  Status: {response.status}")
except Exception as e:
    print(f"  Error: {e}")

# Example 4: POST with explicit method
print("\n4. Explicit POST Method")
print("-" * 40)
data = urllib.parse.urlencode({'test': 'data'}).encode()

try:
    req = urllib.request.Request(url, data=data, method='POST')
    print(f"  Method: {req.method}")
    print(f"  Has data: {req.data is not None}")
except Exception as e:
    print(f"  Error: {e}")

# Example 5: Form submission simulation
print("\n5. Simulate Form Submission")
print("-" * 40)
form_fields = {
    'search': 'python urllib',
    'category': 'documentation',
    'sort': 'relevance'
}

encoded_form = urllib.parse.urlencode(form_fields).encode('utf-8')

try:
    req = urllib.request.Request(url, data=encoded_form)
    print(f"  Form fields: {list(form_fields.keys())}")
    print(f"  Encoded length: {len(encoded_form)} bytes")
except Exception as e:
    print(f"  Error: {e}")

print("\n" + "=" * 60)
print("Key Points:")
print("  - POST requires data parameter")
print("  - Encode data with urlencode()")
print("  - Convert to bytes with encode()")
print("  - Set Content-Type for JSON")
print("  - Request object for custom methods")
print("=" * 60)