feat($Tenacity): integrate Python retry library with Tenacity

Pipfile

@@ -36,6 +36,8 @@ faker = "==14.1.0"
 # A Python module to parse, validate and reformat standard numbers and codes in different formats.
 # It contains a large collection of number formats. https://pypi.org/project/python-stdnum/
 python-stdnum = "==1.17"
+# Retrying library for Python. https://pypi.org/project/tenacity/
+tenacity = "==8.0.1"
 
 [dev-packages]
 # Black is the uncompromising Python code formatter. By using it, you agree to cede control over minutiae of

python_boilerplate/demo/tenacity_usage.py

@@ -0,0 +1,71 @@
+import logging
+import random
+from logging import INFO, WARNING
+from typing import Final
+
+from loguru import logger
+from tenacity import (
+    after_log,
+    retry,
+    retry_if_exception_type,
+    retry_if_result,
+    stop_after_attempt,
+    wait_fixed,
+)
+
+SUCCESS_RANGE: Final = range(200, 300)
+loging_logger: Final = logging.getLogger(__name__)
+
+
+# https://tenacity.readthedocs.io/en/latest/
+# https://jamesfheath.com/2020/07/python-library-tenacity.html
+
+
+@retry(stop=stop_after_attempt(3), after=after_log(loging_logger, WARNING))
+def exception_function_1() -> None:
+    logger.warning("Mocking failure 1")
+    raise RuntimeError("Failure message 1")
+
+
+@retry(
+    stop=stop_after_attempt(3), wait=wait_fixed(2), after=after_log(loging_logger, INFO)
+)
+def exception_function_2() -> None:
+    logger.warning("Mocking failure 2")
+    raise RuntimeError("Failure message 2")
+
+
+@retry(stop=stop_after_attempt(3), retry=retry_if_exception_type((IOError, ValueError)))
+def different_exceptions_possible(x: int) -> str:
+    if x == 1:
+        logger.error("IO Error because x is 1")
+        raise IOError
+    elif x == 2:
+        logger.error("Connection Error because x is 2")
+        raise ConnectionError
+    elif x == 3:
+        logger.error("Type Error because x is 3")
+        raise TypeError
+    else:
+        return "success"
+
+
+def validate_code(result: int) -> bool:
+    needs_retry = result not in SUCCESS_RANGE
+    if needs_retry:
+        logger.warning(
+            f"The result = {result}, which is NOT 2xx code, needs_retry = {needs_retry}"
+        )
+    else:
+        logger.info(
+            f"The result = {result}, which is 2xx code, needs_retry = {needs_retry}"
+        )
+    return needs_retry
+
+
+@retry(stop=stop_after_attempt(3), retry=retry_if_result(validate_code))
+def customized_retry_logic_function(input_int: int) -> int:
+    random_int = random.randint(0, 200)
+    result = input_int + random_int
+    logger.info(f"input_int + random_int = {input_int} + {random_int} = {result}")
+    return result

tests/demo/test_tenacity_usage.py

@@ -0,0 +1,36 @@
+import pytest
+from tenacity import RetryError
+
+from python_boilerplate.demo.tenacity_usage import (
+    customized_retry_logic_function,
+    different_exceptions_possible,
+    exception_function_1,
+    exception_function_2,
+)
+
+
+def test_exception_function_1():
+    with pytest.raises(RetryError):
+        exception_function_1()
+
+
+def test_exception_function_2():
+    with pytest.raises(RetryError):
+        exception_function_2()
+
+
+def test_different_exceptions_possible():
+    with pytest.raises(RetryError):
+        different_exceptions_possible(1)
+    with pytest.raises(RetryError):
+        different_exceptions_possible(2)
+    with pytest.raises(TypeError):
+        different_exceptions_possible(3)
+    assert different_exceptions_possible(4) == "success"
+
+
+def test_customized_retry_logic_function():
+    try:
+        customized_retry_logic_function(240)
+    except Exception as ex:
+        assert True, f"Test passed even if exception raised, {ex.__str__()}"