curl vs Python requests — Full Comparison with Side-by-Side Examples

# curl — simplest form:
curl https://api.example.com/users

# curl with verbose output (shows headers):
curl -v https://api.example.com/users

# Python requests — simple GET:
import requests
response = requests.get('https://api.example.com/users')
print(response.status_code)    # 200
print(response.json())          # parsed JSON dict/list
print(response.headers)         # response headers
print(response.elapsed)         # request timing

# curl with query params:
curl "https://api.example.com/users?page=2&limit=10"

# Python (auto-encodes to URL):
response = requests.get(
    'https://api.example.com/users',
    params={'page': 2, 'limit': 10}
    # → GET /users?page=2&limit=10
)

# Always check for errors:
response.raise_for_status()  # raises HTTPError for 4xx/5xx
data = response.json()

# Custom headers:
# curl:
curl -H "Authorization: Bearer mytoken" \
     -H "X-Custom-Header: value" \
     -H "Accept: application/json" \
     https://api.example.com/protected

# Python requests:
response = requests.get(
    'https://api.example.com/protected',
    headers={
        'Authorization': 'Bearer mytoken',
        'X-Custom-Header': 'value',
        'Accept': 'application/json',
    }
)

# Basic auth:
# curl:
curl -u username:password https://api.example.com

# Python:
response = requests.get(url, auth=('username', 'password'))

# Digest auth:
from requests.auth import HTTPDigestAuth
response = requests.get(url, auth=HTTPDigestAuth('user', 'pass'))

# API key in header:
# curl -H "X-API-Key: your_key" https://api.example.com
response = requests.get(url, headers={'X-API-Key': 'your_key'})

# curl single file upload:
curl -X POST -F "file=@photo.jpg" -F "user_id=123" \
  https://api.example.com/upload

# Python equivalent:
with open('photo.jpg', 'rb') as f:
    response = requests.post(
        'https://api.example.com/upload',
        files={'file': f},
        data={'user_id': '123'}
    )

# With custom filename and content type:
response = requests.post(
    url,
    files={'file': ('custom_name.jpg', open('photo.jpg','rb'), 'image/jpeg')}
)

# Multiple files:
response = requests.post(url, files=[
    ('images', ('photo1.jpg', open('photo1.jpg', 'rb'), 'image/jpeg')),
    ('images', ('photo2.jpg', open('photo2.jpg', 'rb'), 'image/jpeg')),
])

# curl maintains cookies with -c (write) and -b (read):
curl -c cookies.txt https://api.example.com/login \
  -X POST -d "user=alice&pass=secret"

# Use saved cookies in subsequent requests:
curl -b cookies.txt https://api.example.com/dashboard

# Python requests.Session() handles cookies automatically:
import requests
session = requests.Session()

# Set default headers for ALL session requests:
session.headers.update({
    'Authorization': 'Bearer mytoken',
    'User-Agent': 'MyApp/1.0',
})

# Login (Set-Cookie headers stored automatically):
session.post('https://api.example.com/login',
             json={'user': 'alice', 'pass': 'secret'})

# Cookies and headers automatically included in subsequent requests:
dashboard = session.get('https://api.example.com/dashboard')
profile = session.get('https://api.example.com/me')

# Session also reuses TCP connections (connection pooling) → 30-50% faster

# curl timeouts and SSL:
curl --connect-timeout 5 --max-time 30 https://api.example.com
curl -k https://api.example.com  # skip SSL verification
curl --cacert /path/to/ca.pem https://api.example.com

# Python requests equivalents:
# Separate connect timeout and read timeout:
response = requests.get(url, timeout=(5, 30))  # (connect_sec, read_sec)
response = requests.get(url, timeout=30)        # applies to both

# Skip SSL (dev only — never in production):
import urllib3
urllib3.disable_warnings()
response = requests.get(url, verify=False)

# Custom CA bundle:
response = requests.get(url, verify='/path/to/ca.pem')

# Client certificate:
# curl --cert client.crt --key client.key https://api.example.com
response = requests.get(url, cert=('client.crt', 'client.key'))