feat(strings): is unique string

Author: BrianLusina

pystrings/is_unique/README.md

@@ -0,0 +1,6 @@
+# Is unique
+
+Determine whether a string is unique or not. Assume that the input string will only contain alphabets or spaces.
+
+![](./is_unique_example.png)
+

pystrings/is_unique/__init__.py

@@ -0,0 +1,21 @@
+from collections import defaultdict
+from typing import DefaultDict
+
+
+def is_unique(input_str: str) -> bool:
+    """
+    Checks if the input string contains unique characters.
+    Args:
+        input_str (str): the input string to evaluate
+    Returns:
+        bool: True if the input string contains unique characters, False otherwise.
+    """
+    frequency_map: DefaultDict[str, int] = defaultdict(int)
+
+    for char in input_str:
+        if char not in frequency_map:
+            frequency_map[char] = 1
+        else:
+            return False
+
+    return True

pystrings/is_unique/is_unique_example.png

@@ -0,0 +1,45 @@
+import unittest
+from . import is_unique
+
+
+class IsUniqueTestCases(unittest.TestCase):
+
+    def test_1(self):
+        """should return true for abCDefGh"""
+        input_string = "abCDefGh"
+        actual = is_unique(input_string)
+        self.assertTrue(actual)
+
+    def test_2(self):
+        """should return false for nonunique"""
+        input_string = "nonunique"
+        actual = is_unique(input_string)
+        self.assertFalse(actual)
+
+    def test_3(self):
+        """should return true for abCedFghI"""
+        input_string = "abCedFghI"
+        actual = is_unique(input_string)
+        self.assertTrue(actual)
+
+    def test_4(self):
+        """should return false for I Am Not Unique"""
+        input_string = "I Am Not Unique"
+        actual = is_unique(input_string)
+        self.assertFalse(actual)
+
+    def test_5(self):
+        """should return False for heythere"""
+        input_string = "heythere"
+        actual = is_unique(input_string)
+        self.assertFalse(actual)
+
+    def test_6(self):
+        """should return True for hi"""
+        input_string = "hi"
+        actual = is_unique(input_string)
+        self.assertTrue(actual,)
+
+
+if __name__ == '__main__':
+    unittest.main()