如何从具有字母的行和列中获取单词？

Question

doing an assignment and struck to this problem

def board_contains_word(board, word):
    '''(list of list of str, str) -> bool

    Return True if and only if word appears in board.

    Precondition: board has at least one row and one column.

    >>> board_contains_word([['A', 'N', 'T', 'T'], ['X', 'S', 'O', 'B']], 'ANT')
    True
    '''
 return word in board

but i am getting FALSE

Thanks in advance

Answer 1

The python in operator works a bit differently from how you're using it. Here are some examples:

>>> 'laughter' in 'slaughter'
True
>>> 1 in [1,6,5]
True
>>> 'eta' in ['e','t','a']
False
>>> 'asd' in ['asdf','jkl;']
False
>>> 

As you can see, it's got two major uses: testing to see if a string can be found in another string, and testing to see if an element can be found in an array. Also note that the two uses can't be combined.

Now, about solving your problem. You'll need some sort of loop for going through all of the rows one by one. Once you've picked out a single row, you'll need some way to join all of the array elements together. After that, you can figure out if the word is in the board.

Note: this only solves the problem of searching horizontally. Dunno if that's the whole assignment. You can adapt this method to searching vertically using the zip function.

Answer 2

Here's something to get you unstuck:

def board_contains_word(board, word):
    # check accross
    for row in board:
        return word in ''.join(row):

    # try with board's rows and columns transposed
    for row in zip(*board):
        return word in ''.join(row):

    return False

print board_contains_word([['A', 'N', 'T', 'T'], ['X', 'S', 'O', 'B']], 'ANT')
print board_contains_word([['A', 'N', 'T', 'T'], ['X', 'S', 'O', 'B']], 'TO')

Hint: You could simplify things by using the any() function.