ToconnecttoadatabaseinPython,usetheappropriatelibraryforthedatabasetype.1.ForSQLite,usesqlite3withconnect()andmanagewithcursorandcommit.2.ForMySQL,installmysql-connector-pythonandprovidecredentialsinconnect().3.ForPostgreSQL,installpsycopg2andconfigu

def is suitable for complex functions, supports multiple lines, document strings and nesting; lambda is suitable for simple anonymous functions and is often used in scenarios where functions are passed by parameters. The situation of selecting def: ① The function body has multiple lines; ② Document description is required; ③ Called multiple places. When choosing a lambda: ① One-time use; ② No name or document required; ③ Simple logic. Note that lambda delay binding variables may throw errors and do not support default parameters, generators, or asynchronous. In actual applications, flexibly choose according to needs and give priority to clarity.

To set up MySQL logs for auditing or troubleshooting, the key is to select the appropriate log type and configure it correctly. 1. Enable general query logging to record all SQL statements, which are suitable for auditing, but may affect performance; 2. Enable slow query log recognition inefficient queries, suitable for long-term activation; 3. Use binary logs for data recovery and replication, and server_id and log retention time must be configured; 4. Check error logs to locate startup or runtime problems, which are usually enabled by default. Enable corresponding logs according to actual needs to avoid system overload.

Yes, you can parse HTML tables using Python and Pandas. First, use the pandas.read_html() function to extract the table, which can parse HTML elements in a web page or string into a DataFrame list; then, if the table has no clear column title, it can be fixed by specifying the header parameters or manually setting the .columns attribute; for complex pages, you can combine the requests library to obtain HTML content or use BeautifulSoup to locate specific tables; pay attention to common pitfalls such as JavaScript rendering, encoding problems, and multi-table recognition.

The way to access nested JSON objects in Python is to first clarify the structure and then index layer by layer. First, confirm the hierarchical relationship of JSON, such as a dictionary nested dictionary or list; then use dictionary keys and list index to access layer by layer, such as data "details"["zip"] to obtain zip encoding, data "details"[0] to obtain the first hobby; to avoid KeyError and IndexError, the default value can be set by the .get() method, or the encapsulation function safe_get can be used to achieve secure access; for complex structures, recursively search or use third-party libraries such as jmespath to handle.

In Python's for loop, use the continue statement to skip some operations in the current loop and enter the next loop. When the program executes to continue, the current loop will be immediately ended, the subsequent code will be skipped, and the next loop will be started. For example, scenarios such as excluding specific values ??when traversing the numeric range, skipping invalid entries when data cleaning, and skipping situations that do not meet the conditions in advance to make the main logic clearer. 1. Skip specific values: For example, exclude items that do not need to be processed when traversing the list; 2. Data cleaning: Skip exceptions or invalid data when reading external data; 3. Conditional judgment pre-order: filter non-target data in advance to improve code readability. Notes include: continue only affects the current loop layer and will not

MySQL's slow query log is an important tool for optimizing database performance. It helps locate performance bottlenecks by recording SQL statements whose execution time exceeds a specified threshold. 1. Enable slow query log to set slow_query_log, slow_query_log_file and long_query_time parameters in the configuration file; 2. Use mysqldumpslow or pt-query-digest tools to analyze logs, and pay attention to key fields such as Query_time, Lock_time, Rows_sent and Rows_examined; 3. Common problems include the lack of indexing that leads to full table scanning, unreasonable query design, and sorting

super()inPythonisusedtocallmethodsfromparentclasses,particularlyusefulinmultipleinheritance.1.Itavoidshard-codingparentclassnames,improvingcodeflexibility.2.super()followsthemethodresolutionorder(MRO)todeterminewhichparentmethodtocall.3.Inmultipleinh