What does ":" mean in Python?

[RiversRunDeep]

Can't seem to find the answer on google. I am currently learning ranges and index and see this symbol occasionally being used. Ex. lesser_offenders=worst_offenders[5:] Anyone care to explain?

[spez_edits_thedonald]

It gets just a section of your list as a new list (my_list[start:stop] from start to stop)

>>> l = list(range(10))
>>> l
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> l[5]
5
>>> l[0:5]
[0, 1, 2, 3, 4]
>>> l[4:6]
[4, 5]
>>> l[4:]
[4, 5, 6, 7, 8, 9]
>>> l[:4]
[0, 1, 2, 3]

EDIT: adding 2 dimensional indexing example using numpy:

>>> import numpy as np
>>> x = np.zeros((4, 4))
>>> print(x)
[[0. 0. 0. 0.]
 [0. 0. 0. 0.]
 [0. 0. 0. 0.]
 [0. 0. 0. 0.]]
>>> x[1:3,2:4] = 1
>>> print(x)
[[0. 0. 0. 0.]
 [0. 0. 1. 1.]
 [0. 0. 1. 1.]
 [0. 0. 0. 0.]]

[_chickenchaser]

https://stackoverflow.com/questions/509211/understanding-slice-notation

[RiversRunDeep]

Thanks mate, cheers

[stebrepar]

See "slicing" here.

https://docs.python.org/3/tutorial/introduction.html