>>> str = 'abcdefg'
>>> print(str[2:])
cdefg
>>> print(str[:2])
ab
>>> print(str[2:3])
c
>>> print(str[2:6])
cdef
>>> print(str[:-1])
abcdef
>>> print(str[-1:])
g
>>> print(str[-3:-4])
>>> print(str[-3:-1])
ef
>>> print(str[-3:0])
>>> print(str[-3:])
efg