Removed support for Python 2.7 as it is end of life

Removed python 2.7 support since it's end of life and also the new openpyxl was giving some precision issues in 2.7.

The code has been made Python 3 compiliant with pylint and flake8. There is also some refactoring.

.github/workflows/ci.yml

@@ -5,25 +5,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["2.7", "3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
         os: [ubuntu-latest, windows-latest, macos-latest]
         exclude:
-          - python-version: "2.7"
-            os: ubuntu-latest
           - python-version: "3.6"
             os: ubuntu-latest
         include:
           - python-version: "3.6"
             os: ubuntu-20.04
-          - python-version: "2.7"
-            os: ubuntu-20.04
-            pylint-rcfile: "--rcfile=.pylintrc-27"
-          - python-version: "2.7"
-            os: macos-latest
-            pylint-rcfile: "--rcfile=.pylintrc-27"
-          - python-version: "2.7"
-            os: windows-latest
-            pylint-rcfile: "--rcfile=.pylintrc-27"
     runs-on: ${{matrix.os}} 
     steps:
       - uses: actions/checkout@v3

.pylintrc

@@ -87,13 +87,6 @@ disable=missing-module-docstring,
         missing-class-docstring,
         missing-function-docstring,
         duplicate-code,
-        useless-object-inheritance,  # Not 2.7 compatible
-        consider-using-f-string,  # Not 2.7 compatible
-        consider-using-dict-items,  # Not 2.7 compatible
-        super-with-arguments,  # Not 2.7 compatible
-        raise-missing-from,  # Not 2.7 compatible
-        redundant-u-string-prefix,  # Not 2.7 compatible
-        unspecified-encoding,  # Not 2.7 compatible
         invalid-name,  # Workaround (https://github.com/PyCQA/pylint/issues/8319)
 
 # Enable the message, report, category or checker with the given id(s). You can
@@ -158,7 +151,7 @@ max-spelling-suggestions=4
 
 # Spelling dictionary name. Available dictionaries: none. To make it work,
 # install the 'python-enchant' package.
-spelling-dict=
+spelling-dict=en_GB
 
 # List of comma separated words that should be considered directives if they
 # appear and the beginning of a comment and should not be checked.