Python

Opening a file using with statement is preferred as function open implements the context manager protocol that releases the resource when it is outside of the with block. Not doing so requires you to manually release the resource.

Do not use yield inside a comprehension as it will return a generator object. Use a generator expression instead.

Note: Use of yield inside a comprehension was allowed till Python 3.7 but is a syntax error from Python 3.8 onwards.

Raising a built-in or a custom exception when assert fails is ineffective. Asserts always raise an AssertionError, making the provided exception which the user is expecting useless. This may lead to runtime errors if this detail is not understood during the exception handling. It is therefore recommended to use if to check the condition and raise the expression explicitly if something is not right.

Debuggers should only be used temporarily and locally. It is highly recommended not to leave debug statements in checked-in code. This may cause your application to have unintended side-effects.

The I/O operation is being performed on a resource that is closed. This will lead to a runtime error. It is recommended to perform I/O operation on files inside with blocks, as the file is automatically closed when the scope of with ends.