What is the use of "assert" in Python?
In Python, the assert
statement is used to check if a certain condition is true, and if it is not true, raise an exception. The basic syntax of the assert
statement is as follows:
assert some_condition, some_error_message
Here, some_condition
is the condition that you want to check, and some_error_message
is an optional error message that will be displayed if the condition is not true. If some_condition
is true, nothing happens and the program continues to execute. If some_condition
is false, an AssertionError
is raised with the error message passed to the assert
statement.
For example, let's say you have a variable x
that should always be positive, you can use assert statement to check this, like below:
This will raise an error: "AssertionError: x should be positive"
The assert statement is often used as a debugging aid, as it allows you to quickly check if a certain condition is true or not, and raises an error with a helpful message if it is not true. It should be noted that assert statements can be globally disabled by passing -O or -OO while running the python script or program , which can be useful in certain situations.