SCWP(Beta) - Learn Classes and Objects by Building a Sudoku Solver - Step 73: Accepting wrong solution

[andrebdinis]

Describe the Issue

The step asks for a list comprehension, but the following code is accepted as a solution (with parenthesis):
row_str = (str(i) for i in row)

Affected Page

https://www.freecodecamp.org/learn/scientific-computing-with-python/learn-classes-and-objects-by-building-a-sudoku-solver/step-73

Your code

def __str__(self):
        board_str = ''
        for row in self.board:
            row_str = (str(i) for i in row)

Expected behavior

I believe the step must only accept the list comprehension with square brackets []:
row_str = [str(i) for i in row]

Screenshots

No response

System

• Device: Laptop
• OS: Windows 11
• Browser: Brave
• Version: 1.64.116

Additional context

No response

[Dario-DC]

Thank you for reporting this issue. I don't think this is a huge problem, since the code works well with a generator expression too. However, since the instructions are asking for a list comprehension, it makes sense to fix the test.

The helpers do not discriminate between the various comprehension types, so I'd import the ast module and check if the value of the row_str variable is an instance of ast.ListComp. This additional check should take place within this test.