How to read excel files in a for loop with openpyxl?
<p>This seems tricky for me. Let's say I have, nested in a directory tree, an excel file with a few non-empty columns. I want to get the sum of all values located in column F with <code>openpyxl</code>:</p>

<pre><code>file1.xlsx
A  B  C  D  E  F
               5
               7
               11
               17
               20
               29
               34
</code></pre>

<p>My take on it would be as follows, but it is wrong:</p>

<pre><code>import os
from openpyxl import load_workbook

directoryPath=r'C:\Users\MyName\Desktop\MyFolder' #The main folder
os.chdir(directoryPath)
folder_list=os.listdir(directoryPath)
for folders, sub_folders, file in os.walk(directoryPath): #Traversing the sub folders
    for name in file:
        if name.endswith(".xlsx"):
            filename = os.path.join(folders, name)
            wb=load_workbook(filename, data_only=True)
            ws=wb.active
            cell_range = ws['F1':'F7'] #Selecting the slice of interest
            sumup=0
            for row in cell_range:
                sumup=sumup+cell.value
</code></pre>

<p>While running this I get <code>NameError: name 'cell' is not defined</code>. How to work around this?</p>