How to increment a number with the form x.y.z with the use of indexing and all numbers to the right of it become 0

Question

I'm having trouble with trying to increment a specific number that is in the form x.y.z using an index and making all numbers to the right of it become 0.

The final product should look like this:

4.2.11 => 4.3.0

I've tried putting x.y.z into a list so I can retrieve any value I want with an index but can't make them increment in any way.

Answer 1

Only converting the one needed number to int, and by default incrementing the last number:

def increment(version, index=-1):
    nums = version.split('.')
    v = int(nums[index])
    nums[index:] = '0' * len(nums[index:])
    nums[index] = str(v + 1)
    return '.'.join(nums)

print(increment("4.2.11", 0))  # => 5.0.0
print(increment("4.2.11", 1))  # => 4.3.0
print(increment("4.2.11", 2))  # => 4.2.12
print(increment("4.2.11"))     # => 4.2.12

Try it online!

Answer 2

Convert the number to a list with split, and convert the list items to ints so you can increment one of them; then convert back to str and join to produce a string in the original format.

>>> def bump(version, index):
...     nums = [int(i) for i in version.split(".")]
...     nums[index] += 1
...     nums[index+1:] = [0] * (len(nums) - index - 1)
...     return ".".join(str(i) for i in nums)
...
>>> bump("4.2.11", 1)
'4.3.0'
>>> bump("4.2.11", 0)
'5.0.0'
>>> bump("4.2.11", 2)
'4.2.12'

Answer 3

Keep the digits in a list and make a class to encapsulate the behaviour.

class X:
    def __init__(self,x):
        self.digits = [int(n) for n in x.split('.')]
    def __getitem__(self,item):
        return self.digits[item]
    def __setitem__(self,item,value):
        self.digits[item] = value
        for i in range(item+1,len(self.digits)):
            self.digits[i] = 0
    def __str__(self):
        temp = '.'.join('{}' for _ in self.digits)
        return temp.format(*self.digits)

>>> x = X('4.3.11')
>>> str(x)
'4.3.11'
>>> x[1] += 1
>>> str(x)
'4.4.0'
>>> x[0] += 1 
>>> str(x)    
'5.0.0'
>>>