Update 2026-04-25-leetcode-python-general.md

Author: ly16

_posts/2026-04-25-leetcode-python-general.md

@@ -13,6 +13,38 @@ tags:
 
 #### Array
 #### String
+1. list sort
+```python
+# in original list
+a = [3, 1, 2]
+a.sort()
+print(a)  # [1, 2, 3]
+
+# in new sorted list
+a = [3, 1, 2]
+b = sorted(a)
+print(b)  # [1, 2, 3]
+print(a)  # keep the same
+```
+
+2. sort parameters
+
+Using Timsort, which is a combination of insertion sort(small runs) and merge sort(merge sorted runs)
+
+- time = best O(n), avg and worst O(nlogn)
+- space = O(n)
+
+
+```python
+# descending sort
+a.sort(reverse=True)
+
+a = [(1, 3), (2, 1), (4, 2)]
+a.sort(key=lambda x: x[1]) # by second variable
+a = [(1, 3), (1, 2), (2, 1)]
+a.sort(key=lambda x: (x[0], x[1])) # by sort first variable and then second variable
+a.sort(key=lambda x: (x[0], -x[1]))
+```
 #### Binary Search
 
 1. Find the index of the first appearance (nums[index] <= target)