What structural model does mysql database belong to?

Install pyodbc: Use the pipinstallpyodbc command to install the library; 2. Connect SQLServer: Use the connection string containing DRIVER, SERVER, DATABASE, UID/PWD or Trusted_Connection through the pyodbc.connect() method, and support SQL authentication or Windows authentication respectively; 3. Check the installed driver: Run pyodbc.drivers() and filter the driver name containing 'SQLServer' to ensure that the correct driver name is used such as 'ODBCDriver17 for SQLServer'; 4. Key parameters of the connection string

Introduction to Statistical Arbitrage Statistical Arbitrage is a trading method that captures price mismatch in the financial market based on mathematical models. Its core philosophy stems from mean regression, that is, asset prices may deviate from long-term trends in the short term, but will eventually return to their historical average. Traders use statistical methods to analyze the correlation between assets and look for portfolios that usually change synchronously. When the price relationship of these assets is abnormally deviated, arbitrage opportunities arise. In the cryptocurrency market, statistical arbitrage is particularly prevalent, mainly due to the inefficiency and drastic fluctuations of the market itself. Unlike traditional financial markets, cryptocurrencies operate around the clock and their prices are highly susceptible to breaking news, social media sentiment and technology upgrades. This constant price fluctuation frequently creates pricing bias and provides arbitrageurs with

shutil.rmtree() is a function in Python that recursively deletes the entire directory tree. It can delete specified folders and all contents. 1. Basic usage: Use shutil.rmtree(path) to delete the directory, and you need to handle FileNotFoundError, PermissionError and other exceptions. 2. Practical application: You can clear folders containing subdirectories and files in one click, such as temporary data or cached directories. 3. Notes: The deletion operation is not restored; FileNotFoundError is thrown when the path does not exist; it may fail due to permissions or file occupation. 4. Optional parameters: Errors can be ignored by ignore_errors=True

Install the corresponding database driver; 2. Use connect() to connect to the database; 3. Create a cursor object; 4. Use execute() or executemany() to execute SQL and use parameterized query to prevent injection; 5. Use fetchall(), etc. to obtain results; 6. Commit() is required after modification; 7. Finally, close the connection or use a context manager to automatically handle it; the complete process ensures that SQL operations are safe and efficient.

The recommended way to read files line by line in Python is to use withopen() and for loops. 1. Use withopen('example.txt','r',encoding='utf-8')asfile: to ensure safe closing of files; 2. Use forlineinfile: to realize line-by-line reading, memory-friendly; 3. Use line.strip() to remove line-by-line characters and whitespace characters; 4. Specify encoding='utf-8' to prevent encoding errors; other techniques include skipping blank lines, reading N lines before, getting line numbers and processing lines according to conditions, and always avoiding manual opening without closing. This method is complete and efficient, suitable for large file processing

threading.Timer executes functions asynchronously after a specified delay without blocking the main thread, and is suitable for handling lightweight delays or periodic tasks. ①Basic usage: Create Timer object and call start() method to delay execution of the specified function; ② Cancel task: Calling cancel() method before the task is executed can prevent execution; ③ Repeating execution: Enable periodic operation by encapsulating the RepeatingTimer class; ④ Note: Each Timer starts a new thread, and resources should be managed reasonably. If necessary, call cancel() to avoid memory waste. When the main program exits, you need to pay attention to the influence of non-daemon threads. It is suitable for delayed operations, timeout processing, and simple polling. It is simple but very practical.

TorunaPythonscriptwithargumentsinVSCode,configurelaunch.jsonbyopeningtheRunandDebugpanel,creatingoreditingthelaunch.jsonfile,andaddingthedesiredargumentsinthe"args"arraywithintheconfiguration.2.InyourPythonscript,useargparseorsys.argvtoacce

Use multiprocessing.Queue to safely pass data between multiple processes, suitable for scenarios of multiple producers and consumers; 2. Use multiprocessing.Pipe to achieve bidirectional high-speed communication between two processes, but only for two-point connections; 3. Use Value and Array to store simple data types in shared memory, and need to be used with Lock to avoid competition conditions; 4. Use Manager to share complex data structures such as lists and dictionaries, which are highly flexible but have low performance, and are suitable for scenarios with complex shared states; appropriate methods should be selected based on data size, performance requirements and complexity. Queue and Manager are most suitable for beginners.