Obtaining OAuth 2.0 Client Credentials Token

import requests
import os

def get_oauth_token(token_url, client_id, client_secret, scope=None):
    """
    Obtains an OAuth 2.0 access token using the Client Credentials flow.
    
    Args:
        token_url (str): The OAuth 2.0 token endpoint URL.
        client_id (str): The client ID provided by the OAuth provider.
        client_secret (str): The client secret provided by the OAuth provider.
        scope (str, optional): A space-separated string of desired scopes.
    
    Returns:
        str: The access token if successful, None otherwise.
    """
    
    headers = {
        "Content-Type": "application/x-www-form-urlencoded"
    }
    
    data = {
        "grant_type": "client_credentials",
        "client_id": client_id,
        "client_secret": client_secret
    }
    
    if scope:
        data["scope"] = scope
        
    try:
        response = requests.post(token_url, headers=headers, data=data)
        response.raise_for_status() # Raise an HTTPError for bad responses (4xx or 5xx)
        
        token_data = response.json()
        access_token = token_data.get("access_token")
        
        if not access_token:
            print("Error: Access token not found in response.")
            return None
        
        return access_token
        
    except requests.exceptions.HTTPError as e:
        print(f"HTTP Error obtaining token: {e}")
        print(f"Response: {response.text}")
    except requests.exceptions.RequestException as e:
        print(f"Request Error obtaining token: {e}")
    except ValueError:
        print("Error: Could not parse JSON response.")
        
    return None

# Example Usage:
if __name__ == "__main__":
    # It's best practice to store sensitive information in environment variables
    TOKEN_URL = os.getenv("OAUTH_TOKEN_URL", "https://example.com/oauth/token")
    CLIENT_ID = os.getenv("OAUTH_CLIENT_ID", "your_client_id")
    CLIENT_SECRET = os.getenv("OAUTH_CLIENT_SECRET", "your_client_secret")
    API_SCOPE = os.getenv("OAUTH_API_SCOPE", "read write")

    token = get_oauth_token(TOKEN_URL, CLIENT_ID, CLIENT_SECRET, API_SCOPE)

    if token:
        print(f"Successfully obtained token: {token[:30]}...")
        # Use the token to make subsequent API calls
        # For example:
        # api_response = requests.get("https://example.com/api/data", headers={"Authorization": f"Bearer {token}"})
        # print(api_response.json())
    else:
        print("Failed to obtain OAuth token.")