TypeError: 'generator' object is not subscriptable

Error in chapter 12, which produces the following "TypeError: 'generator' object is not subscriptable" for the code below. 



>>> import openpyxl
>>> wb = openpyxl.load_workbook('example.xlsx')
>>> sheet = wb.active
>>> sheet = wb.active
>>> sheet.columns[1]
Traceback (most recent call last):
  File "<pyshell#4>", line 1, in <module>
    sheet.columns[1]
TypeError: 'generator' object is not subscriptable
>>> 

RESOLUTION: 
Create a list for the sheet.colums: 
list(sheet.columns)[1] to overcome the generator error - outdated method since python 2 apparently. 

Trouble Using Pip and Installing Openpyxl

Openpyxl is, according to Automate the Boring Stuff with Python, supposed to be a handy python library which allows programmers to use python programs with Microsoft excel sheets.

But first you need to install pip on your machine.

What is pip?

"Pip is a package manager for python packages. A package contains all the files you need for a module. Modules are Python code libraries that you can include in your project". - W3 schools. 

The first difficulty I had was getting pip to work through my command line.  I resolved that issue using paths - as described in this video (https://www.youtube.com/watch?v=Jw_MuM2BOuI).

The next issue I had was with installing openpyxl itself (which you need pip to do). I received the following error:

"Could not install packages due to an EnvironmentError: [Errno 13] Permission denied:"

"Consider using the `--user` option or check the permissions" 

Eventually, I found a solution on stackoverflow, which suggested using the following:

python -m pip install --user openpyxl

This worked.