diff --git a/maths/inter_quartile_range.py b/maths/inter_quartile_range.py
index 3ef4a2694..8dd33879d 100644
--- a/maths/inter_quartile_range.py
+++ b/maths/inter_quartile_range.py
@@ -47,7 +47,7 @@ def inter_quartile_range(x: np.array) -> float:
     if length == 0:
         raise ValueError
     x.sort()
-    q1 = find_median(x[0: length // 2])
+    q1 = find_median(x[0 : length // 2])
     half_length = (length // 2) + 1 if length % 2 else length // 2
     q3 = find_median(x[half_length:length])
     return q3 - q1