assert in python

`assert` is a statement in Python that can be used to test if a condition is true. If the condition is not true, the program will raise an AssertionError with an optional error message.

The syntax for assert statement is:

assert condition, [error message]

Here, `condition` is the expression that is tested, and `error message` is an optional argument that can be provided to specify the error message to be displayed when the assertion fails.

If the condition is true, nothing happens and the program continues to execute normally. If the condition is false, the program raises an AssertionError with the specified error message, or a default error message if no message is specified.

For example:

x = 5
assert x == 5, "x is not equal to 5"

In this example, the assert statement tests if the value of `x` is equal to 5. Since `x` is indeed equal to 5, the program continues to execute normally. However, if `x` was not equal to 5, the program would have raised an AssertionError with the error message "x is not equal to 5".