add testcase for several strips of utils

tests/utils/test_strips.py

@@ -0,0 +1,23 @@
+from pylib.utils import strips, lstrips, rstrips
+
+
+def test_lstrips():
+    assert lstrips('foobbar', '') == 'foobbar'
+    assert lstrips('foobar', 'fo') == 'obar'
+    assert lstrips('foofoobar', 'foo') == 'foobar'
+    assert lstrips('foobarbaz', ('foo', 'bar')) == 'baz'
+    assert lstrips('foobarbaz', ('bar', 'foo')) == 'barbaz'
+
+
+def test_rstrips():
+    assert rstrips('foobbar', '') == 'foobbar'
+    assert rstrips('foobbar', 'bar') == 'foob'
+    assert rstrips('foobarbar', 'bar') == 'foobar'
+    assert rstrips('fozfoobar', ('bar', 'foo')) == 'foz'
+    assert rstrips('fozfoobar', ('foo', 'bar')) == 'fozfoo'
+
+
+def test_strips():
+    assert strips('foobarfoo', '') == 'foobarfoo'
+    assert strips('foobarfoo', 'foo') == 'bar'
+    assert strips('foobarfoo', ('foo', 'bar')) == ''