The key to dealing with API authentication is to understand and use the authentication method correctly. 1. APIKey is the simplest authentication method, usually placed in the request header or URL parameters; 2. BasicAuth uses username and password for Base64 encoding transmission, which is suitable for internal systems; 3. OAuth2 needs to obtain the token first through client_id and client_secret, and then bring the BearerToken in the request header; 4. In order to deal with the token expiration, the token management class can be encapsulated and automatically refreshed the token; in short, selecting the appropriate method according to the document and safely storing the key information is the key.

In Python, the method of traversing tuples with for loops includes directly iterating over elements, getting indexes and elements at the same time, and processing nested tuples. 1. Use the for loop directly to access each element in sequence without managing the index; 2. Use enumerate() to get the index and value at the same time. The default index is 0, and the start parameter can also be specified; 3. Nested tuples can be unpacked in the loop, but it is necessary to ensure that the subtuple structure is consistent, otherwise an unpacking error will be raised; in addition, the tuple is immutable and the content cannot be modified in the loop. Unwanted values can be ignored by \_. It is recommended to check whether the tuple is empty before traversing to avoid errors.

Pure functions in Python refer to functions that always return the same output with no side effects given the same input. Its characteristics include: 1. Determinism, that is, the same input always produces the same output; 2. No side effects, that is, no external variables, no input data, and no interaction with the outside world. For example, defadd(a,b):returna b is a pure function because no matter how many times add(2,3) is called, it always returns 5 without changing other content in the program. In contrast, functions that modify global variables or change input parameters are non-pure functions. The advantages of pure functions are: easier to test, more suitable for concurrent execution, cache results to improve performance, and can be well matched with functional programming tools such as map() and filter().

Python implements asynchronous API calls with async/await with aiohttp. Use async to define coroutine functions and execute them through asyncio.run driver, for example: asyncdeffetch_data(): awaitasyncio.sleep(1); initiate asynchronous HTTP requests through aiohttp, and use asyncwith to create ClientSession and await response result; use asyncio.gather to package the task list; precautions include: avoiding blocking operations, not mixing synchronization code, and Jupyter needs to handle event loops specially. Master eventl

In Python, although there is no built-in final keyword, it can simulate unsurpassable methods through name rewriting, runtime exceptions, decorators, etc. 1. Use double underscore prefix to trigger name rewriting, making it difficult for subclasses to overwrite methods; 2. judge the caller type in the method and throw an exception to prevent subclass redefinition; 3. Use a custom decorator to mark the method as final, and check it in combination with metaclass or class decorator; 4. The behavior can be encapsulated as property attributes to reduce the possibility of being modified. These methods provide varying degrees of protection, but none of them completely restrict the coverage behavior.

ifelse is the infrastructure used in Python for conditional judgment, and different code blocks are executed through the authenticity of the condition. It supports the use of elif to add branches when multi-condition judgment, and indentation is the syntax key; if num=15, the program outputs "this number is greater than 10"; if the assignment logic is required, ternary operators such as status="adult"ifage>=18else"minor" can be used. 1. Ifelse selects the execution path according to the true or false conditions; 2. Elif can add multiple condition branches; 3. Indentation determines the code's ownership, errors will lead to exceptions; 4. The ternary operator is suitable for simple assignment scenarios.

To display hidden files and folders, you can achieve it in the following three ways: 1. Click the "View" tab in File Explorer and check "Hidden Projects" to temporarily display hidden content; 2. Set the global display of hidden files through folder options, and the path is "View" → "Options" → "View" tab to select "Show hidden files, folders and drives" in the tab; 3. Advanced users can modify the Hidden item value to 1 through the registry to take effect permanently, and the registry must be backed up before operation. The above method is suitable for different usage scenarios and can be selected according to your needs.

Want to use Python to crawl website content? The answer is: choose the right tool, understand the web structure, and deal with common problems. 1. Install the requests library and send requests, use headers and time.sleep() to avoid backcrawling; 2. Use BeautifulSoup to parse HTML to extract data, such as links and titles; 3. Pagination construct URL loop crawl, and dynamic content is controlled by Selenium; 4. Pay attention to setting User-Agent, controlling request frequency, complying with robots protocol, and adding exception handling. By mastering these key points, you can quickly get started with Python crawlers.