Extracting Specific Keys from JSON Lists and Downloading Images with Python

The article begins by describing a Python function def extract_key_from_json_list(json_list, key): extracted_list = [] for json_obj in json_list: if key in json_obj: extracted_list.append(json_obj[key]) return extracted_list that iterates over a list of JSON objects, checks for the presence of a specified key, and builds a new list containing the corresponding values.

An example demonstrates extracting the "name" field from a sample list of dictionaries, producing ['Alice', 'Bob', 'Charlie'] as output.

The article then introduces a second function for downloading images: import os import requests def download_images(image_list, output_folder): if not os.path.exists(output_folder): os.makedirs(output_folder) for index, image_url in enumerate(image_list): try: response = requests.get(image_url) response.raise_for_status() file_name = str(index) + '.jpg' # numeric index as filename file_path = os.path.join(output_folder, file_name) with open(file_path, 'wb') as file: file.write(response.content) print(f"Downloaded {file_name}") except requests.exceptions.RequestException as e: print(f"Error downloading image at index {index}: {str(e)}") # Example usage image_urls = [ 'https://example.com/image1.jpg', 'https://example.com/image2.jpg', 'https://example.com/image3.jpg' ] output_folder = 'images' # folder to store images download_images(image_urls, output_folder) . This function creates the target folder if needed, iterates over the URL list with enumerate , downloads each image, saves it with a numeric filename, and logs success or errors.

Finally, an extended version of the extraction function shows how to exclude JSON objects where the type field equals 3: def extract_key_from_json_list(json_list, key): extracted_list = [] for json_obj in json_list: if json_obj.get('type') != 3 and key in json_obj: extracted_list.append(json_obj[key]) return extracted_list . An example list with various type values demonstrates that the function returns only the names of objects whose type is not 3.