CODEWITHSUNDEEP
pythonlistloopswhile-loopiteration
j.g
j.g

Reputation: 13

Loop through a list in Python, increasing the values whilst also moving through the list on each iteration

Here is my code, which is used to provide row numbers in excel:

clusters = 3
rowRef = [9, 12, 15]

x = 1
while x < clusters:
    rowRef[x:] = [a + 1 for a in rowRef]
    x = x + 1

The output I'm looking to achieve is:

So with each iteration of the loop it changes one less item from the list. However, the output I get is:

[9, 10, 10, 11, 14, 17]

What do I need to change for this to work?

Upvotes: 1

Views: 262

Answers (2)

nicholishen
nicholishen

Reputation: 3012

Here's a mathematical shortcut to achieve your desired output with more efficient code. 

rowRef = [9, 12, 15]

for i in range(1, len(rowRef)):
  rowRef[i] += i

print(rowRef)

Upvotes: 0

Netwave
Netwave

Reputation: 42746

You lack one more slicing on your list comprehension:

rowRef[x:] = [a + 1 for a in rowRef[x:]]

Otherwise, you are iterating through the whole list instead of the remaining list to process each time.

Here you have the live example

Upvotes: 2

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