add textutils module.

.gitignore

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+__pycache__

test_textutitls.py

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+import textutils
+import unittest
+
+class TestTextUtils(unittest.TestCase):
+    def test_positive_tokens(self):
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", 0), "")
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", 1), "hello")
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", 2), "hello/world")
+
+        
+    def test_negative_tokens(self):
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", -1), "doing")
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", -2), "you/doing")
+
+    def test_n_exceed_length(self):
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", 8), "hello/world/how/are/you/doing")
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing", "/", -6), "hello/world/how/are/you/doing")
+
+    def test_delim_at_the_begining(self):
+        self.assertEqual(textutils.create_n_tokens("/hello/world/how/are/you/doing/", "/", 0), "")
+        self.assertEqual(textutils.create_n_tokens("/hello/world/how/are/you/doing/", "/", 1), "")
+        self.assertEqual(textutils.create_n_tokens("/hello/world/how/are/you/doing/", "/", 2), "/hello")
+
+    def test_delim_at_the_end(self):
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing/", "/", -1), "")
+        self.assertEqual(textutils.create_n_tokens("hello/world/how/are/you/doing/", "/", -2), "doing/")
+
+if __name__ == '__main__':
+    unittest.main()

textutils.py

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+def create_n_tokens(str, delim, n):
+    parts = str.split(delim)
+
+    if n > 0 :
+        return delim.join(parts[0: n])
+    else :
+        l = len(parts)
+        start = l + n
+        if start < 0: start = 0
+
+        return delim.join(parts[start: l])