Working with APIs in Python

Working with APIs in Python

Python allows easy interaction with APIs (Application Programming Interfaces) to fetch, send, or update data from web services.

1. Installing Required Library

• Most API interactions use the requests library:

pip install requests

import requests

2. Making GET Requests

• Retrieve data from an API endpoint.

url = "https://jsonplaceholder.typicode.com/posts/1"
response = requests.get(url)

# Check status
print(response.status_code)  # 200 = success

# Get response as JSON
data = response.json()
print(data)

3. Making POST Requests

• Send data to an API endpoint.

url = "https://jsonplaceholder.typicode.com/posts"
payload = {
    "title": "foo",
    "body": "bar",
    "userId": 1
}

response = requests.post(url, json=payload)
print(response.status_code)
print(response.json())

4. Handling Headers and Authentication

url = "https://api.example.com/data"
headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
}

response = requests.get(url, headers=headers)
print(response.json())

5. Query Parameters

url = "https://api.example.com/search"
params = {"q": "Python", "limit": 5}

response = requests.get(url, params=params)
print(response.json())

6. Error Handling

try:
    response = requests.get(url, timeout=5)
    response.raise_for_status()  # Raises HTTPError for bad responses
    data = response.json()
except requests.exceptions.HTTPError as errh:
    print("HTTP Error:", errh)
except requests.exceptions.ConnectionError as errc:
    print("Connection Error:", errc)
except requests.exceptions.Timeout as errt:
    print("Timeout Error:", errt)
except requests.exceptions.RequestException as err:
    print("Error:", err)

7. Working with JSON Data

# Access JSON fields
print(data['title'])

# Loop through list of items
for item in data:
    print(item['id'], item['title'])

8. Key Points

• GET: Retrieve data from an API.

• POST: Send data to an API.

• Headers: Required for authentication and content-type.

• Params: Pass query parameters for filtering or search.

• Error handling: Always handle connection and HTTP errors.

• JSON: Most APIs return data in JSON format; Python dictionaries can be used to parse it.