如何扩展某些选定行的列大小以及如何添加2D数组python2.7的其他行

Question

I need a 2D array with a fixed array name (say 'grids'), which can take variable row and variable column size based on certain conditions. Like if the first condition is satisfied, then that will add a row to 'grids' and if other condition satisfies, then a new column has to be added - ONLY to that particular row of 'grids'. I considered a 15X15 2D array (assuming 15 being the largest row as well as column that could possibly be added) and initialized all with zeros.

Then whenever first condition satisfied, I added some value to the element of the row, and if next condition satisfied, then added some set of columns to a specific row, while the rest elements being zero. While I assume this being a big and long way of doing, and storing unnecessary elements in the array, I also wish to have the rows to have continuous non-zero elements so that I can use consequent (row) elements to calculate, say the distance between them.

I wonder if there is any easy way of dealing with this problem? - adding rows to an existing array, each row having varying column, array name being same! Thanks

Answer 1

Maybe you tried that already but :

grids = [[1,2,3], [4,5,6,7,8], [10,11,12]]
print grids 

# Will give you : [[1,2,3], [4,5,6,7,8], [10,11,12]]

Here, you have different number of columns for each row, does it help ?

Adding a column to the 2nd row is like :

grids[1].append(9)
# Will give you : [[1,2,3], [4,5,6,7,8,9], [10,11,12]]

Adding a row will be like :

grids.append([13,14])
# Will give you : [[1,2,3], [4,5,6,7,8,9], [10,11,12], [13, 14]]