Development (#17)

* reverse string

* Formatted with psf/black

* remove whitespace

* Formatted with psf/black

* format code

* Formatted with psf/black

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

Author: realDuYuanChao

strings/remove_whitespace.py

@@ -0,0 +1,32 @@
+def remove_whitespace(original: str) -> str:
+    """
+    >>> remove_whitespace("I Love Python")
+    'ILovePython'
+    >>> remove_whitespace("I    Love       Python")
+    'ILovePython'
+    >>> remove_whitespace('    I     Love     Python')
+    'ILovePython'
+    >>> remove_whitespace("")
+    ''
+    """
+    return "".join(original.split())
+
+
+def remove_whitespace2(original: str) -> str:
+    """
+    >>> remove_whitespace2("I Love Python")
+    'ILovePython'
+    >>> remove_whitespace2("I    Love       Python")
+    'ILovePython'
+    >>> remove_whitespace2('    I     Love     Python')
+    'ILovePython'
+    >>> remove_whitespace2("")
+    ''
+    """
+    return original.replace(" ", "")
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()

strings/reverse.py

@@ -0,0 +1,41 @@
+def reverse(original: str) -> str:
+    """
+    >>> reverse("abc")
+    'cba'
+    >>> reverse('1234')
+    '4321'
+    >>> reverse("cba321")
+    '123abc'
+    >>> reverse("")
+    ''
+    """
+    return original[::-1]
+
+
+def reverse2(original: str) -> str:
+    """
+    >>> reverse2("abc")
+    'cba'
+    >>> reverse2('1234')
+    '4321'
+    >>> reverse2("cba321")
+    '123abc'
+    >>> reverse2("")
+    ''
+    """
+    original = list(original)
+    i, j = 0, len(original) - 1
+    while i < j:
+        original[i], original[j] = (
+            original[j],
+            original[i],
+        )
+        i += 1
+        j -= 1
+    return "".join(original)
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()