From d546e8d659d6f2f486b5b4000e2003218c711f54 Mon Sep 17 00:00:00 2001
From: SemyonSinchenko <semyonsinchenko@yahoo.com>
Date: Tue, 21 Nov 2023 23:20:41 +0100
Subject: [PATCH 1/2] Add random laplace number and div_or_else function

 On branch feature/random-fenerators
 Changes to be committed:
	new file:   quinn/math.py
---
 quinn/math.py | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 quinn/math.py

diff --git a/quinn/math.py b/quinn/math.py
new file mode 100644
index 00000000..203d27f9
--- /dev/null
+++ b/quinn/math.py
@@ -0,0 +1,50 @@
+"""Math routines for PySpark."""
+from typing import Optional, Union
+
+from pyspark.sql import Column
+from pyspark.sql import functions as F  # noqa: N812
+
+
+def rand_laplace(
+    mu: Union[float, Column],
+    beta: Union[float, Column],
+    seed: Optional[int] = None,
+) -> Column:
+    """Generate random numbers from Laplace(mu, beta).
+
+    :param mu: mu parameter of Laplace distribution
+    :param beta: beta parameter of Laplace distribution
+    :param seed: random seed value (optional, default None)
+    :returns: column with random numbers
+    """
+    if not isinstance(mu, Column):
+        mu = F.lit(mu)
+
+    if not isinstance(beta, Column):
+        beta = F.lit(beta)
+
+    u = F.rand(seed)
+
+    return (
+        F.when(u < F.lit(0.5), mu + beta * F.log(2 * u))
+        .otherwise(mu - beta * F.log(2 * (1 - u)))
+        .alias("laplace_random")
+    )
+
+
+def div_or_else(
+    cola: Column,
+    colb: Column,
+    default: Union[float, Column] = 0.0,
+) -> Column:
+    """Return result of division of cola by colb or default if colb is zero.
+
+    :param cola: dividend
+    :param colb: divisor
+    :param default: default value
+    :returns: result of division or zero
+    """
+    if not isinstance(default, Column):
+        default = F.lit(default)
+
+    return F.when(colb == F.lit(0.0), default).otherwise(cola / colb)

From 3c777373f0444a64f2101a6c22469f9a3538bd3e Mon Sep 17 00:00:00 2001
From: SemyonSinchenko <semyonsinchenko@yahoo.com>
Date: Tue, 21 Nov 2023 23:29:04 +0100
Subject: [PATCH 2/2] Add import from __future__

 On branch feature/random-fenerators
 Changes to be committed:
	modified:   quinn/math.py
---
 quinn/math.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/quinn/math.py b/quinn/math.py
index 203d27f9..0302f9ad 100644
--- a/quinn/math.py
+++ b/quinn/math.py
@@ -1,4 +1,6 @@
 """Math routines for PySpark."""
+from __future__ import annotations
+
 from typing import Optional, Union
 
 from pyspark.sql import Column