is subsequence

setup.cfg

@@ -1,8 +1,5 @@
 [bdist_wheel]
-universal = 1
-
-[metadata]
-license_file = LICENSE
+universal = true
 
 [coverage:run]
 branch = True

setup.py

@@ -1,12 +1,12 @@
-from setuptools import find_packages, setup
+from setuptools import setup
 
 setup(
-    name='wimpy',
-    version='0.4',
-    description='Anti-copy-pasta',
-    url='https://github.com/wimglenn/wimpy',
-    author='Wim Glenn',
-    author_email='hey@wimglenn.com',
-    license='MIT',
-    packages=find_packages(exclude=['tests']),
+    name="wimpy",
+    version="0.5",
+    description="Anti-copy-pasta",
+    url="https://github.com/wimglenn/wimpy",
+    author="Wim Glenn",
+    author_email="hey@wimglenn.com",
+    license="MIT",
+    packages=["wimpy"],
 )

tests/test_util.py

@@ -3,28 +3,35 @@
 
 import pytest
 
+from wimpy import WimpyError
 from wimpy import cached_property
 from wimpy import ceiling_division
 from wimpy import chunks
 from wimpy import grouper
+from wimpy import is_subsequence
 from wimpy import strip_prefix
 from wimpy import strip_suffix
-from wimpy import WimpyError
 from wimpy import working_directory
 
 
-@pytest.mark.parametrize('in_,pre,out', [
-    ('www.yahoo.com', 'www.', 'yahoo.com'),
-    ('www.yahoo.com', 'Www.', 'www.yahoo.com'),
-])
+@pytest.mark.parametrize(
+    "in_,pre,out",
+    [
+        ("www.yahoo.com", "www.", "yahoo.com"),
+        ("www.yahoo.com", "Www.", "www.yahoo.com"),
+    ],
+)
 def test_strip_prefix(in_, pre, out):
     assert strip_prefix(in_, pre) == out
 
 
-@pytest.mark.parametrize('in_,suf,out', [
-    ('www.yahoo.com', 'www.', 'www.yahoo.com'),
-    ('www.yahoo.com', '.com', 'www.yahoo'),
-])
+@pytest.mark.parametrize(
+    "in_,suf,out",
+    [
+        ("www.yahoo.com", "www.", "www.yahoo.com"),
+        ("www.yahoo.com", ".com", "www.yahoo"),
+    ],
+)
 def test_strip_suffix(in_, suf, out):
     assert strip_suffix(in_, suf) == out
 
@@ -45,11 +52,11 @@ def prop(self):
 
 def test_cached_property():
     a = A()
-    assert 'prop' not in a.__dict__
+    assert "prop" not in a.__dict__
     x = a.prop
-    assert 'prop' in a.__dict__
+    assert "prop" in a.__dict__
     y = a.prop
-    assert 0. < x == y < 1.
+    assert 0.0 < x == y < 1.0
     del a.prop  # invalidate cache
     z = a.prop  # prop recomputed
     assert x == y != z
@@ -60,45 +67,48 @@ def test_cached_property():
     assert isinstance(A.prop, cached_property)
 
 
-@pytest.mark.parametrize('numerator,denominator,result', [
-    (51, 10, 6),
-    (50, 10, 5),
-    (49, 10, 5),
-    (-49, 10, -4),
-])
+@pytest.mark.parametrize(
+    "numerator,denominator,result",
+    [(51, 10, 6), (50, 10, 5), (49, 10, 5), (-49, 10, -4)],
+)
 def test_ceiling_div(numerator, denominator, result):
     assert ceiling_division(numerator, denominator) == result
 
 
-
-@pytest.mark.parametrize('iterable,n,fillvalue,result', [
-    (range(6), 2, None, [(0, 1), (2, 3), (4, 5)]),
-    (range(5), 2, None, [(0, 1), (2, 3), (4, None)]),
-    (range(5), 2, 123, [(0, 1), (2, 3), (4, 123)]),
-])
+@pytest.mark.parametrize(
+    "iterable,n,fillvalue,result",
+    [
+        (range(6), 2, None, [(0, 1), (2, 3), (4, 5)]),
+        (range(5), 2, None, [(0, 1), (2, 3), (4, None)]),
+        (range(5), 2, 123, [(0, 1), (2, 3), (4, 123)]),
+    ],
+)
 def test_grouper(iterable, n, fillvalue, result):
     assert list(grouper(iterable, n, fillvalue)) == result
 
 
-@pytest.mark.parametrize('iterable,chunk_size,overlap,result', [
-    ('1234567', 3, 0, [('1', '2', '3'), ('4', '5', '6'), ('7',)]),
-    ('123456', 3, 0, [('1', '2', '3'), ('4', '5', '6')]),
-    ('123456', 4, 2, [('1', '2', '3', '4'), ('3', '4', '5', '6')]),
-    ('', 3, 0, []),
-])
+@pytest.mark.parametrize(
+    "iterable,chunk_size,overlap,result",
+    [
+        ("1234567", 3, 0, [("1", "2", "3"), ("4", "5", "6"), ("7",)]),
+        ("123456", 3, 0, [("1", "2", "3"), ("4", "5", "6")]),
+        ("123456", 4, 2, [("1", "2", "3", "4"), ("3", "4", "5", "6")]),
+        ("", 3, 0, []),
+    ],
+)
 def test_chunks(iterable, chunk_size, overlap, result):
     assert list(chunks(iterable, chunk_size, overlap)) == result
 
 
 def test_chunks_doesnt_get_stuck_due_to_small_chunk_size():
-    gen = chunks('123456', chunk_size=0)
-    with pytest.raises(WimpyError, match='chunk size too small'):
+    gen = chunks("123456", chunk_size=0)
+    with pytest.raises(WimpyError, match="chunk size too small"):
         next(gen)
 
 
 def test_chunks_doesnt_get_stuck_due_to_big_overlap():
-    gen = chunks('123456', chunk_size=3, overlap=3)
-    with pytest.raises(WimpyError, match='overlap too large'):
+    gen = chunks("123456", chunk_size=3, overlap=3)
+    with pytest.raises(WimpyError, match="overlap too large"):
         next(gen)
 
 
@@ -108,3 +118,22 @@ def test_chunks_from_infinite_generator():
     assert next(g) == (0, 0, 0, 0, 0)
     assert next(g) == (0, 0, 0, 0, 0)
     assert next(g) == (0, 0, 0, 0, 0)
+
+
+@pytest.mark.parametrize(
+    "needle,haystack,result",
+    [
+        ("23", "1234", True),
+        ("32", "1234", False),
+        ("24", "1234", True),
+        ("1234", "1234", True),
+        ("1234", "123", False),
+        ("113", "112233", True),
+        ("1113", "112233", False),
+        ("", "x", True),
+        ("", "", True),
+        ("x", "", False),
+    ],
+)
+def test_is_subsequence(needle, haystack, result):
+    assert is_subsequence(needle, haystack) == result

wimpy/__init__.py

@@ -1,4 +1,4 @@
 from wimpy.exceptions import WimpyError
 from wimpy.util import *
 
-__version__ = '0.4'
+__version__ = "0.5"

wimpy/util.py

@@ -8,14 +8,24 @@
 from wimpy.exceptions import WimpyError
 
 
-__all__ = ['cached_property', 'working_directory', 'strip_prefix', 'strip_suffix', 'ceiling_division', 'grouper', 'chunks']
+__all__ = [
+    "cached_property",
+    "working_directory",
+    "strip_prefix",
+    "strip_suffix",
+    "ceiling_division",
+    "grouper",
+    "chunks",
+    "is_subsequence",
+]
 
 
 class cached_property(object):
     """
     non-data descriptor: property is computed once per instance and then replaces itself
     with an ordinary attribute.  Deleting the attribute invalidates the cache.
     """
+
     def __init__(self, func):
         update_wrapper(self, func)
         self.func = func
@@ -41,22 +51,22 @@ def working_directory(path):
 def strip_prefix(s, prefix):
     """Removes the prefix, if it's there, otherwise returns input string unchanged"""
     if s.startswith(prefix):
-        return s[len(prefix):]
+        return s[len(prefix) :]
     return s
 
 
 def strip_suffix(s, suffix):
     """Removes the suffix, if it's there, otherwise returns input string unchanged"""
     if s.endswith(suffix):
-        return s[:len(s) - len(suffix)]
+        return s[: len(s) - len(suffix)]
     return s
 
 
 def ceiling_division(numerator, denominator):
     """Divide and round up"""
     # Implementation relies on Python's // operator using floor division (round down)
     # This might surprise C users who expect rounding towards zero
-    return -(-numerator//denominator)
+    return -(-numerator // denominator)
 
 
 def grouper(iterable, n, fillvalue=None):
@@ -87,4 +97,14 @@ def chunks(iterable, chunk_size=3, overlap=0):
     except StopIteration:
         # if the iterator is exhausted, yield any remaining elements
         if i > 0:
-            yield tuple(queue)[-i-overlap:]
+            yield tuple(queue)[-i - overlap :]
+
+
+def is_subsequence(needle, haystack):
+    """Are all the elements of needle contained in haystack, and in the same order?
+    There may be other elements interspersed throughout"""
+    it = iter(haystack)
+    for element in needle:
+        if element not in it:
+            return False
+    return True