In [1]: x = "anmxcjkwnekmjkldm!^%@(*)#_+@78935014712jksdfs"
In [2]: len(x)
Out[2]: 45
Now, For positive index ranges for x is from 0 to 44 (i.e. length - 1)
In [3]: x[0]
Out[3]: 'a'
In [4]: x[45]
---------------------------------------------------------------------------
IndexError Traceback (most recent call last)
/home/<ipython console> in <module>()
IndexError: string index out of range
In [5]: x[44]
Out[5]: 's'
For Negative index, index ranges from -1 to -45
In [6]: x[-1]
Out[6]: 's'
In [7]: x[-45]
Out[7]: 'a
For negative index, negative [length -1] i.e. the last valid value of positive index will give second list element as the list is read in reverse order,
In [8]: x[-44]
Out[8]: 'n'
Other, index's examples,
In [9]: x[1]
Out[9]: 'n'
In [10]: x[-9]
Out[10]: '7'