
Excel Column Number

Given a string that represents the column title as appears in an Excel sheet, return its corresponding column number.
But how does the Excel column numbering actually work? Well, the column number is like decimal number, but with base (radix) 26 and "digits" A-Z. Read more about number bases. Let's look at the exact numbers:
Excel Decimal A 1 .. Z 26
The 1-"digit" numbers have ended. 2-"digits" numbers start from double first "digit" and go to double last one:
Excel Decimal A 1 .. Z 26 AA 27 .. AZ 52 BA 53 .. BZ 78 CA 79 .. .. ZZ 702
Now it's turn for 3-"digit" numbers...
Input: A string (str).
Output: An integer (int).
Examples:
assert column_number("A") == 1 assert column_number("Z") == 26 assert column_number("AB") == 28 assert column_number("ZY") == 701
Precondition: Non empty, only upper case, only English letters
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=py config --key=
Sync solutions into your local folder
checkio sync
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin
checkio install-plugin --ff
checkio install-plugin --chromium
Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.