Yes, that's helpful. Thanks a lot.
But what if I wanna construct an array of arrays like we do in C++ or Java:
myArray [][]
Basically, I want to do the following in Python:
myArray[0][1] = list1 myArray[1][2] = list2 myArray[2][3] = list3
How to do this, gurus?
You might be able to get by with:
py> arr = [[] for _ in range(10)] py> arr [[], [], [], [], [], [], [], [], [], []]
But perhaps not:
py> arr[0][1] = 1 Traceback (most recent call last): File "<interactive input>", line 1, in ? IndexError: list assignment index out of range
If you know the default value, you might consider:
py> arr = [[0]*10 for _ in range(10)]
py> arr[0][1] = 1
py> arr
[[0, 1, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]]
although if you're planning on doing this kind of stuff, you should definitely check out the numarray module.
Generally though, I find that a dict with tuple keys is the better solution here:
py> d = {}
py> d[0,1] = 1
py> d[2,3] = 1
py> d[0,1]
1
py> d.get((4, 5), 0)
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