sort in 2d array python code example
Example 1: sort by index 2d array python
a = [[9, 9, 2], [9, 9, 3], [9, 9, 8], [9, 9, 4], [9, 9, 1], [9, 9, 5]]
b = sorted(a, key=lambda a:a[2])
#b contains the following arrays, sorted by their second index:
[[9, 9, 1], [9, 9, 2], [9, 9, 3], [9, 9, 4], [9, 9, 5], [9, 9, 8]]
Example 2: python sort a 2d array by custom function
>>> a = [
[12, 18, 6, 3],
[ 4, 3, 1, 2],
[15, 8, 9, 6]
]
>>> a.sort(key=lambda x: x[1])
>>> a
[[4, 3, 1, 2],
[15, 8, 9, 6],
[12, 18, 6, 3]]