how to initialize a 2d array in python code example

Example 1: python initialize a 2d array

x = [[foo for i in range(10)] for j in range(10)]
# x is now a 10x10 array of 'foo' (which can depend on i and j if you want)

Example 2: how to create 2d list in python

o=[]
for i in range(0,rows):
    x=[]
    for j in range(0,cols):
        x.append(0)
    o.append(x)
#if you use [[0]*cols]*rows all rows will become the same list
#so editing in one row will edit all rows

Example 3: create a 2d array in python

def build_matrix(rows, cols):
    matrix = []

    for r in range(0, rows):
        matrix.append([0 for c in range(0, cols)])

    return matrix

if __name__ == '__main__':
    build_matrix(6, 10)

Example 4: 2d array python initialize

[[element] * numcols] * numrows

Example 5: initialise a 2d array python

x = [[foo for i in range(10)] for j in range(10)]
# x is now a 10x10 array of 'foo' (which can depend on i and j if you want)

Example 6: 2d array python initialize

>>> b = [['a']*3]*3
>>> b
[['a', 'a', 'a'], ['a', 'a', 'a'], ['a', 'a', 'a']]
>>> b[1][1]
'a'
>>> b[1][1] = 'b'
>>> b
[['a', 'b', 'a'], ['a', 'b', 'a'], ['a', 'b', 'a']]