Python tips

Random Python tips I collect recently.

1. IMMUTABLE: String, Tuple, Bytes, Booleans, Numbers
2. MUTABLE: List, Dic, Set
3. Tuple() can use [], but NO add or append
4. Set {}, no order, can NOT use [], {1,2}.add(3), NO DUPLICATE
5. String can use [], but immutable, str[0] = c would fail
6. [x]*10 will generate 10 refer to the SAME x, change 1 will change ALL
7. [[] for _ in range(10)] instead
8. print(f’{value=}’) I love it
9. list(dict) == list(disk.keys())
10. a=b=123, other useage may have side effect
11. 10<= a <30 works in Python
12. list(range(1,n+1))
13. ans.append(list_b) vs ans.append(list_b[:]). Future modification of list_b may have side effect