To count how many consecutive pairs in a list of numbers

To count how many consecutive pairs of number in a list, here’s an example:

[150,151,152,262]

There are 2 consecutive pairs, which are 150 & 151, 151 & 152.

I try below:

import more_itertools as mit
import itertools

iterable = [150,151,152,262]

tem_list = [list(group) for group in mit.consecutive_groups(iterable)]
# [[150, 151, 152], [262]]

i = 0
for t in tem_list:
    if len(t) == 1:
        i = 0
    if len(t) == 2:
        i += 1
    if len(t) == 3:
        i += 2      
print (i)

But it doesn’t work. What went wrong, and how can I correct it?

>Solution :

Using a grouping function for this is overkill. You can use zip() to pair each item with its successor and add the result of comparing them using the sum function:

L = [150,151,152,262]
C = sum(a+1==b for a,b in zip(L,L[1:]))
print(C) # 2