CODEWITHSUNDEEP
python
Pedro
Pedro

Reputation: 143

Gives me True every time Python

I have tab that is a tuple with three tuples and each has 3 elements that can only be 1, -1 or 0. I want a function to receive a tab an evaluate if it is True or False. This is what I came up with:

tab = ((0,0,-1),(-1,1,0),(1,0))

def board(tab):
    if len(tab) != 3: 
        return False
    else:
        for row in tab:
            if len(row) != 3: 
                return False
            else:
                for element in row:
                    if element not in (-1, 0, 1):
                        return False
                    else:
                        return True

The problem is that with the current tab it says true and it should be false. Also if anything is something besides 1,-1 and 0 it should return False and if I say tab = ((0,0,-1),(-1,1,0),(1,0,2)) it returns True. What's the problem?

Upvotes: 0

Views: 67

Answers (3)

Ponyboy
Ponyboy

Reputation: 86

Your issue is your return statement of true, because of this return if any element is ok the entire function will return true, where in actuality you want the function to return false if any of the conditions are not met. You can remedy this by moving the return true to the end of the function so all of the elements must be tested before the function can be returned true. This is shown below and passes both of the test cases you mentioned

tab =  ((0,0,-1),(-1,1,0),(1,0,2))
def board(tab):
    if len(tab) != 3: 
        return False
    else:
        for row in tab:
            if len(row) != 3: 
                return False
            else:
                for element in row:
                    if element not in (-1, 0, 1):
                        return False
        return True

Upvotes: 1

Dave Mcsavvy
Dave Mcsavvy

Reputation: 520

You're looping through just one row!!! To understand, make the wrong row come first in the tuple and try it

Upvotes: 1

Pedro
Pedro

Reputation: 143

tab = ((0,0,-1),(-1,1,0),(1,0,2))

def board(tab): if len(tab) != 3: return False

for row in tab:
    if len(row) != 3: 
        return False

for element in row:
    if element not in (-1, 0, 1):
        return False
else:
    return True

Thanks guys!

Upvotes: 1

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