--- a
+++ b/singlecellmultiomics/pyutils/pyutils.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+import math
+import subprocess
+import numpy as np
+
+
+def sorted_slice(a,l,r):
+    start = np.searchsorted(a, l, 'left')
+    end = np.searchsorted(a, r, 'right')
+    return np.arange(start,end)
+
+def meanOfCounter(counter):
+    sum_of_numbers = sum(
+        number * count for number,
+        count in counter.most_common())
+    count = sum(count for n, count in counter.most_common())
+    if count == 0:
+        return 0
+    return sum_of_numbers / count
+
+
+def varianceOfCounter(counter):
+
+    sum_of_numbers = sum(
+        number * count for number,
+        count in counter.most_common())
+    if sum_of_numbers == 0:
+        return 0
+    count = sum(count for n, count in counter.most_common())
+    total_squares = sum(
+        number * number * count for number,
+        count in counter.most_common())
+    mean_of_squares = total_squares / count
+    mean = sum_of_numbers / count
+    variance = mean_of_squares - mean * mean
+    return math.sqrt(variance)
+
+
+def wccount(filename):
+    out = subprocess.Popen(['wc', '-l', filename],
+                           stdout=subprocess.PIPE,
+                           stderr=subprocess.STDOUT
+                           ).communicate()[0]
+    return int(out.partition(b' ')[0])
+
+
+def wccountgz(filename):
+    try:
+        cmd = f'zcat {filename} | wc -l'
+        out = subprocess.Popen(cmd,
+                               stdout=subprocess.PIPE,
+                               stderr=subprocess.STDOUT,
+                               shell=True
+                               ).communicate()[0]
+        return int(out.partition(b' ')[0])
+    except Exception as e:
+        return 0