Add new "divide" and "redivide" functions to split strings in two.

Author: domdfcoding

domdf_python_tools/utils.py

@@ -64,11 +64,12 @@
 import contextlib
 import inspect
 import json
+import re
 import sys
 from io import StringIO
 from math import log10
 from pprint import pformat
-from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, Iterator, List, Optional, Tuple, Union
+from typing import TYPE_CHECKING, Any, Callable, Dict, Iterable, Iterator, List, Optional, Pattern, Tuple, Union
 
 # this package
 import domdf_python_tools.words
@@ -101,6 +102,8 @@
 		"trim_precision",
 		"double_repr_string",
 		"redirect_output",
+		"divide",
+		"redivide",
 		]
 
 #: The current major python version.
@@ -427,3 +430,40 @@ def redirect_output(combine: bool = False) -> Iterator[Tuple[StringIO, StringIO]
 
 	with contextlib.redirect_stdout(stdout), contextlib.redirect_stderr(stderr):
 		yield stdout, stderr
+
+
+def divide(string: str, sep: str) -> Tuple[str, str]:
+	"""
+	Divide a string into two parts, about the given string.
+
+	.. versionadded:: 2.7.0
+
+	:param string:
+	:param sep:
+	"""
+
+	if sep not in string:
+		raise ValueError(f"{sep!r} not in {string!r}")
+
+	parts = string.split(sep, 1)
+	return tuple(parts)  # type: ignore
+
+
+def redivide(string: str, pat: Union[str, Pattern]) -> Tuple[str, str]:
+	"""
+	Divide a string into two parts, splitting on the given regular expression.
+
+	.. versionadded:: 2.7.0
+
+	:param string:
+	:param pat:
+	"""
+
+	if isinstance(pat, str):
+		pat = re.compile(pat)
+
+	if not pat.search(string):
+		raise ValueError(f"{pat!r} has no matches in {string!r}")
+
+	parts = pat.split(string, 1)
+	return tuple(parts)  # type: ignore

tests/test_utils.py

@@ -17,13 +17,15 @@
 # 3rd party
 import click
 import pytest
+from pytest_regressions.data_regression import DataRegressionFixture
 
 # this package
 from domdf_python_tools.testing import testing_boolean_values
 from domdf_python_tools.typing import HasHead
 from domdf_python_tools.utils import (
 		cmp,
 		convert_indents,
+		divide,
 		double_repr_string,
 		enquote_value,
 		head,
@@ -33,6 +35,7 @@
 		printt,
 		pyversion,
 		redirect_output,
+		redivide,
 		stderr_writer,
 		str2tuple,
 		strtobool,
@@ -449,3 +452,47 @@ def test_redirect_output_combine():
 	expected = "I'm going to stdout\nI'm going to stderr\nI'm also going to stdout\nI'm also going to stderr\n"
 	assert stdout.getvalue() == expected
 	assert stderr.getvalue() == expected
+
+
+@pytest.mark.parametrize(
+		"string, sep",
+		[
+				("hello=world", '='),
+				("hello = world", '='),
+				("hello = world", " = "),
+				("hello: world", ':'),
+				("hello: world", ": "),
+				]
+		)
+def test_divide(string: str, sep: str, data_regression: DataRegressionFixture):
+	data = dict(divide(e, sep) for e in [string, string, string])
+
+	data_regression.check(data)
+
+
+def test_divide_errors():
+	with pytest.raises(ValueError, match="'=' not in 'hello: world'"):
+		divide("hello: world", '=')
+
+
+@pytest.mark.parametrize(
+		"string, sep",
+		[
+				("hello=world", r"\s?=\s?"),
+				("hello = world", r"\s?=\s?"),
+				("hello = world", '='),
+				("hello: world", r":\s?"),
+				("hello: world", r"\s?:\s?"),
+				]
+		)
+def test_redivide(string: str, sep: str, data_regression: DataRegressionFixture):
+	data = dict(redivide(e, sep) for e in [string, string, string])
+
+	data_regression.check(data)
+
+
+def test_redivide_errors():
+	with pytest.raises(ValueError, match=r"re.compile\('='\) has no matches in 'hello: world'"):
+		redivide("hello: world", '=')
+	with pytest.raises(ValueError, match=r"re.compile\(.*\) has no matches in 'hello: world'"):
+		redivide("hello: world", r"\d")

tests/test_utils_/test_divide_hello___world___.yml

@@ -0,0 +1 @@
+'hello ': ' world'

tests/test_utils_/test_divide_hello___world_____.yml

@@ -0,0 +1 @@
+hello: world

tests/test_utils_/test_divide_hello__world___.yml

@@ -0,0 +1 @@
+hello: ' world'

tests/test_utils_/test_divide_hello__world____.yml

@@ -0,0 +1 @@
+hello: world

tests/test_utils_/test_divide_hello_world___.yml

@@ -0,0 +1 @@
+hello: world

tests/test_utils_/test_redivide_hello___world___.yml

@@ -0,0 +1 @@
+'hello ': ' world'

tests/test_utils_/test_redivide_hello___world___s____s__.yml

@@ -0,0 +1 @@
+hello: world

tests/test_utils_/test_redivide_hello__world____s__.yml

@@ -0,0 +1 @@
+hello: world