marklap · May 6, 2018 05:32 · May 6, 2018
diff --git a/__init__.py b/__init__.py
@@ -0,0 +1 @@
+''' longest_palindromic_substring package '''
diff --git a/longest_palindromic_substring.py b/longest_palindromic_substring.py
@@ -0,0 +1,22 @@
+''' longest_palindromic_substring finds the longest palindrome substring in a string
+'''
+
+
+def lpss(s):
+    ''' lpss (Longest Palindromic SubString) returns the longest palindrome withing the string
+
+    Args:
+        s (str): string to search
+
+    Returns:
+        str: resultant substring; the first longest palindromic substring
+    '''
+    len_s = len(s)
+    l_pal = ''
+    for j in range(1, len_s+1):
+        for i in range(len_s - j+1):
+            ss = s[i:i+j]
+            if ss == ss[::-1] and len(ss) > len(l_pal):
+                l_pal = ss
+
+    return l_pal
diff --git a/test_longest_palindromic_substring.py b/test_longest_palindromic_substring.py
@@ -0,0 +1,18 @@
+''' test_longest_palindromic_substring tests the longest_palindromic_substring module
+'''
+
+from .longest_palindromic_substring import lpss
+
+
+def test_lpss():
+    cases = [
+        ('These are not the droids you\'re looking for.', 'ese'),
+        ('Ugh, no palindromes!', 'U'),
+        ('racecar', 'racecar'),
+        ('bananarama', 'anana'),
+        ('A but tuba.', 'but tub'),
+        ('My mom did eat a pip.', ' mom '),
+    ]
+    for s, want in cases:
+        got = lpss(s)
+        assert want == got, 'incorrect palindrome - want: {0}, got: {1}'.format(want, got)