Remove Python 2 compatibility and add mypy type checking

.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.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", "3.12", "3.13"]
 
     steps:
     - name: Checkout Code

.gitignore

@@ -7,3 +7,8 @@ files.txt
 *egg-info
 .DS_STORE
 .tox
+.coverage
+.coverage.*
+htmlcov/
+.pytest_cache/
+.mypy_cache/

MANIFEST.in

@@ -1 +1,2 @@
 include CHANGES CREDITS LICENSE *.md *.txt
+include pycoin/py.typed

README.md

@@ -6,7 +6,7 @@ pycoin -- Python Cryptocoin Utilities
 =====================================
 
 The pycoin library implements many utilities useful when dealing with bitcoin and some bitcoin-like
-alt-coins. It has been tested with Python 2.7, 3.7-3.13.
+alt-coins. It requires Python 3.8 or higher.
 
 See also [pycoinnet](http://github.com/richardkiss/pycoinnet/) for a library that speaks the bitcoin protocol.
 

mypy.ini

@@ -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

pycoin/bloomfilter.py

@@ -1,13 +1,14 @@
 import math
 import struct
+from typing import Tuple
 
 from pycoin.encoding.b58 import a2b_hashed_base58
 from pycoin.intbytes import indexbytes
 
 LOG_2 = math.log(2)
 
 
-def filter_size_required(element_count, false_positive_probability):
+def filter_size_required(element_count: int, false_positive_probability: float) -> int:
     # The size S of the filter in bytes is given by
     # (-1 / pow(log(2), 2) * N * log(P)) / 8
     # Of course you must ensure it does not go over the maximum size
@@ -17,23 +18,23 @@ def filter_size_required(element_count, false_positive_probability):
     return min(36000, int(((-1 / pow(LOG_2, 2) * element_count * lfpp)+7) // 8))
 
 
-def hash_function_count_required(filter_size, element_count):
+def hash_function_count_required(filter_size: int, element_count: int) -> int:
     # The number of hash functions required is given by S * 8 / N * log(2).
     return int(filter_size * 8.0 / element_count * LOG_2 + 0.5)
 
 
 class BloomFilter(object):
     MASK_ARRAY = [1 << _ for _ in range(8)]
 
-    def __init__(self, size_in_bytes, hash_function_count, tweak):
+    def __init__(self, size_in_bytes: int, hash_function_count: int, tweak: int) -> None:
         if size_in_bytes > 36000:
             raise ValueError("too large")
         self.filter_bytes = bytearray(size_in_bytes)
         self.bit_count = 8 * size_in_bytes
         self.hash_function_count = hash_function_count
         self.tweak = tweak
 
-    def add_item(self, item_bytes):
+    def add_item(self, item_bytes: bytes) -> None:
         for hash_index in range(self.hash_function_count):
             seed = hash_index * 0xFBA4C795 + self.tweak
             self.set_bit(murmur3(item_bytes, seed=seed) % self.bit_count)
@@ -63,13 +64,13 @@ def check_bit(self, v):
         byte_index, mask = self._index_for_bit(v)
         return (self.filter_bytes[byte_index] & mask) == mask
 
-    def filter_load_params(self):
+    def filter_load_params(self) -> Tuple[bytearray, int, int]:
         return self.filter_bytes, self.hash_function_count, self.tweak
 
 
 # http://stackoverflow.com/questions/13305290/is-there-a-pure-python-implementation-of-murmurhash
 
-def murmur3(data, seed=0):
+def murmur3(data: bytes, seed: int = 0) -> int:
     c1 = 0xcc9e2d51
     c2 = 0x1b873593
 

pycoin/cmds/b58.py

@@ -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/dump.py

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

pycoin/cmds/keychain.py

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

pycoin/cmds/ku.py

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

pycoin/cmds/msg.py

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

pycoin/cmds/tx.py

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

pycoin/coins/SolutionChecker.py

@@ -18,4 +18,4 @@ def check_solution(self, tx_context, traceback_f=None, *args, **kwargs):
         tx_context: information about the transaction that the VM may need
         traceback_f: a function invoked on occasion to check intermediate state
         """
-        raise NotImplemented()
+        raise NotImplementedError()

pycoin/coins/Tx.py

@@ -17,7 +17,7 @@ class Tx(object):
     @classmethod
     def parse(class_, f):
         """Parse a transaction Tx from the file-like object f."""
-        raise NotImplemented()
+        raise NotImplementedError()
 
     @classmethod
     def from_bin(class_, blob):
@@ -53,11 +53,11 @@ def from_hex(class_, hex_string):
         return class_.from_bin(h2b(hex_string))
 
     def __init__(self, *args, **kwargs):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def stream(self, f, *args, **kwargs):
         """Stream a transaction Tx to the file-like object f."""
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def as_bin(self, *args, **kwargs):
         """Returns a binary blob containing the streamed transaction.
@@ -81,7 +81,7 @@ def as_hex(self, *args, **kwargs):
 
     def hash(self, hash_type=None):
         """Return the hash for this Tx object."""
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def id(self):
         """Return the human-readable hash for this Tx object."""
@@ -97,16 +97,16 @@ def tx_outs_as_spendable(self, block_index_available=0):
             for tx_out_index, tx_out in enumerate(self.txs_out)]
 
     def __str__(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def __repr__(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def check(self):
         """
         Basic checks that don't depend on network or block context.
         """
-        raise NotImplemented()
+        raise NotImplementedError()
 
     """
     The functions below here deal with an optional additional parameter: "unspents".

pycoin/coins/TxIn.py

@@ -5,16 +5,16 @@ class TxIn(object):
 
     @classmethod
     def parse(class_, f):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def __init__(self, *args, **kwargs):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def stream(self, f):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def __str__(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
 
 """

pycoin/coins/TxOut.py

@@ -5,16 +5,16 @@ class TxOut(object):
 
     @classmethod
     def parse(class_, f):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def __init__(self, *args, **kwargs):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def stream(self, f):
-        raise NotImplemented()
+        raise NotImplementedError()
 
     def __str__(self):
-        raise NotImplemented()
+        raise NotImplementedError()
 
 
 """

pycoin/ecdsa/intstream.py

@@ -1,40 +1,11 @@
+from typing import Literal
 
-from pycoin.intbytes import iterbytes, byte2int
 
-
-def _to_bytes(v, length, byteorder="big"):
+def to_bytes(v: int, length: int, byteorder: Literal["big", "little"] = "big") -> bytes:
     """This is the same functionality as ``int.to_bytes`` in python 3"""
     return v.to_bytes(length, byteorder=byteorder)
 
 
-def _from_bytes(bytes, byteorder="big", signed=False):
+def from_bytes(data: bytes, byteorder: Literal["big", "little"] = "big", signed: bool = False) -> int:
     """This is the same functionality as ``int.from_bytes`` in python 3"""
-    return int.from_bytes(bytes, byteorder=byteorder, signed=signed)
-
-
-if hasattr(int, "to_bytes"):
-    to_bytes = _to_bytes
-    from_bytes = _from_bytes
-else:
-    def to_bytes(v, length, byteorder="big"):
-        """This is the same functionality as ``int.to_bytes`` in python 3"""
-        ba = bytearray()
-        for i in range(length):
-            mod = v & 0xff
-            v >>= 8
-            ba.append(mod)
-        if byteorder == "big":
-            ba.reverse()
-        return bytes(ba)
-
-    def from_bytes(bytes, byteorder="big", signed=False):
-        """This is the same functionality as ``int.from_bytes`` in python 3"""
-        if byteorder != "big":
-            bytes = reversed(bytes)
-        v = 0
-        for c in iterbytes(bytes):
-            v <<= 8
-            v += c
-        if signed and byte2int(bytes) & 0x80:
-            v = v - (1 << (8*len(bytes)))
-        return v
+    return int.from_bytes(data, byteorder=byteorder, signed=signed)