add floor() (#1551)

* ceil and floor

* ceil and floor

maths/ceil.py

@@ -0,0 +1,18 @@
+def ceil(x) -> int:
+    """
+    Return the ceiling of x as an Integral.
+
+    :param x: the number
+    :return: the smallest integer >= x.
+
+    >>> import math
+    >>> all(ceil(n) == math.ceil(n) for n in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000))
+    True
+    """
+    return x if isinstance(x, int) or x - int(x) == 0 else int(x + 1) if x > 0 else int(x)
+
+
+if __name__ == '__main__':
+    import doctest
+
+    doctest.testmod()

maths/floor.py

@@ -0,0 +1,18 @@
+def floor(x) -> int:
+    """
+    Return the floor of x as an Integral.
+
+    :param x: the number
+    :return: the largest integer <= x.
+
+    >>> import math
+    >>> all(floor(n) == math.floor(n) for n in (1, -1, 0, -0, 1.1, -1.1, 1.0, -1.0, 1_000_000_000))
+    True
+    """
+    return x if isinstance(x, int) or x - int(x) == 0 else int(x) if x > 0 else int(x - 1)
+
+
+if __name__ == '__main__':
+    import doctest
+
+    doctest.testmod()