openpyxl - Reading a next cell value in a loop

Question

I am creating an loop to traverse the cells in sheet. At some conditions i want to access next cell value in a loop.

import openpyxl

wb = openpyxl.load_workbook('test.xlsx')
wb = wb.get_sheet_by_name("Sheet 1")


for row in wb['A1' : 'B150']:
    for cell in row:
        print cell.value  # prints current active cell
        if something:
            # print next cell value

Please suggest a way to access next cell value in a loop. I am using python 2.7. Thanks in advance.

Answer 1

Well, this is not an OpenPyXl specific question, but more a question about iterators.

What you can do is write a function which iterates over a sequence and returns the current and the next item.

For instance:

def iter_curr_next(seq):
    iter_seq = iter(seq)
    curr_item = next(iter_seq)
    next_item = next(iter_seq)  # may raise StopIteration
    yield curr_item, next_item
    while True:
        curr_item = next_item
        next_item = next(iter_seq)  # may raise StopIteration
        yield curr_item, next_item

Note: this function returns the couples (curr_item, next_item) until the last but one.

Here is how you can use this function (for instance, we display the current and next item when the current is an odd number):

row = [1, 2, 3, 5, 6, 5]

for curr_item, next_item in iter_curr_next(row):
    if curr_item % 2 == 1:
        print(curr_item, next_item)

You get:

1 2
3 5
5 6

But, this is a little complex…

What you can do instead is to create a list (or a tuple) and iterate on it that way:

for curr_item, next_item in zip(row[:-1], row[1:]):
    if curr_item % 2 == 1:
        print(curr_item, next_item)

You get the same result.

If fact, when you iterate the rows of a sheet with OpenPyXl, each row is a tuple. So, the previous for loop will work (see: implementation of openpyxl.worksheet.worksheet.Worksheet.get_squared_range function).