Four Time‑Saving Python Tricks to Boost Execution Speed

Python developers can often gain 10‑20% execution speed by applying a few simple techniques.

Reverse a list : Use slicing ( mylist[::-1] ) or the in‑place mylist.reverse() method; timing with python -m timeit shows the built‑in reverse() is faster, though it mutates the original list.

Swap two values : Python allows a one‑line swap without a temporary variable: variable_1, variable_2 = variable_2, variable_1 . The same pattern works for dictionary entries, e.g., md[key_2], md[key_1] = md[key_1], md[key_2] , reducing code length and execution time.

Loop inside a function : Placing a for loop inside a function means the function is called once, avoiding repeated call overhead compared to calling a function inside an external loop. Example code creates a list of strings and defines two functions—one with the loop inside and one without—to illustrate the speed difference.

Reduce function calls : Use isinstance() for type checking (single call) instead of multiple calls to type() or id() . Also, compute expensive expressions like len(a) once before a loop, and import only needed objects ( from X import Y ) to avoid extra lookups.

Overall, leveraging Python’s built‑in functions and concise syntax can noticeably speed up programs while keeping the code clean and readable.