Assignment patterns must be on the left side of assignment

This error message usually occurs when you try to assign a value to a variable or object using an invalid syntax. In Python, the assignment operator (=) requires that the variable or object being assigned to be on the left side, while the value or expression being assigned must be on the right side.

For example, the following code will raise the "Assignment patterns must be on the left side of assignment" error because we are trying to assign the value of 5 to the expression `a + b`:

a = 1
b = 2
a + b = 5

To fix this error, the correct way to assign a value to `a + b` would be to reverse the left and right sides so that the assignment pattern is correct:

a = 1
b = 2
a + b = c  # or some other valid variable name
c = 5

Alternatively, you can use a valid assignment pattern such as assigning a single value to a variable:

a, b = 1, 2
c = a + b

Make sure to double-check your code and ensure that the assignment pattern is correct.