Difference between split and partition is split returns the list without delimiter and will split where ever it gets delimiter in string i.e.
x = 'http://test.com/lalala-134-431'
a,b,c = x.split(-)
print(a)
"http://test.com/lalala"
print(b)
"134"
print(c)
"431"
and partition will divide the string with only first delimiter and will only return 3 values in list
x = 'http://test.com/lalala-134-431'
a,b,c = x.partition('-')
print(a)
"http://test.com/lalala"
print(b)
"-"
print(c)
"134-431"
so as you want last value you can use rpartition it works in same way but it will find delimiter from end of string
x = 'http://test.com/lalala-134-431'
a,b,c = x.partition('-')
print(a)
"http://test.com/lalala-134"
print(b)
"-"
print(c)
"431"