Remove Python 2 compatibility code and add mypy configuration

Co-authored-by: richardkiss <5336+richardkiss@users.noreply.github.com>

Author: Copilot

.github/workflows/mypy.yml

@@ -0,0 +1,37 @@
+name: Type checking with mypy
+
+on:
+  push:
+    branches:
+      - '**'
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  mypy:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    strategy:
+      matrix:
+        python-version: [3.8, "3.10", "3.11"]
+
+    steps:
+    - name: Checkout Code
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - name: Setup Python environment
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install dependencies
+      run: |
+        pip install --upgrade pip
+        pip install mypy>=1.0
+
+    - name: Run mypy
+      run: |
+        mypy pycoin

.github/workflows/test-py27.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       max-parallel: 4
       matrix:
-        python-version: [3.7, 3.8, 3.9, "3.10", "3.11", "3.12", "3.13"]
+        python-version: [3.8, 3.9, "3.10", "3.11"]
 
     steps:
     - name: Checkout Code

.github/workflows/test.yml

@@ -0,0 +1,12 @@
+[mypy]
+python_version = 3.8
+warn_return_any = False
+warn_unused_configs = True
+disallow_untyped_defs = False
+ignore_missing_imports = True
+strict_optional = False
+files = pycoin
+
+# Specific module ignores can be added as needed
+# [mypy-pycoin.contrib.*]
+# ignore_errors = True

mypy.ini

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import print_function
-
 import argparse
 
 from pycoin.encoding.b58 import a2b_base58, b2a_base58, a2b_hashed_base58, b2a_hashed_base58

pycoin/cmds/b58.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 
 import datetime
 

pycoin/cmds/dump.py

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import print_function
-
 import argparse
 import sqlite3
 import sys

pycoin/cmds/keychain.py

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import print_function
-
 import argparse
 import json
 import re

pycoin/cmds/ku.py

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import print_function
-
 import argparse
 import sys
 

pycoin/cmds/msg.py

@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 
-from __future__ import print_function
-
 import argparse
 import calendar
 import codecs