Essential Python Skills that Separate Beginners from Intermediate Programmers

The article explains the differences between beginner and intermediate Python programmers and presents a checklist of essential skills to develop.

Key focus areas include problem solving and asking good questions, understanding the XY problem, grasping why code works or fails, using strings and lists effectively, employing loops, writing proper functions, applying object‑oriented programming, and respecting PEP‑8 style guidelines.

Problem solving and asking questions : Emphasizes that the ability to solve problems is more valuable than merely writing code, and encourages programmers to attempt solutions before seeking help.

XY problem : Describes the XY problem with an example of extracting a file extension. Two solutions are shown: def extract_ext(filename): return filename[-3:] print(extract_ext('photo_of_sasquatch.png')) # >>> png def extract_ext(filename): return filename.split('.')[-1] print(extract_ext('photo_of_sasquatch.png')) print(extract_ext('photo_of_lochness.jpeg')) # >>> png # >>> jpeg

Understanding why code works : Highlights the importance of debugging, using IDE code folding, and visualizing execution with tools like Python Tutor .

String manipulation : Shows indexing and slicing (e.g., word[0] , word[0:5] ), and methods such as endswith() and split() to handle file extensions and other tasks.

List usage : Demonstrates list creation, iteration, mixing types, sorting pitfalls, separating numbers from strings, list comprehensions, and the filter function. Example snippets: my_list = ['a', 'b', 'n', 'x', 1, 2, 3, 'a', 'n', 'b'] for item in my_list: print(f'current item: {item}, Type: {type(item)}') my_list = [1,2,3,'a','b','c'] check_list = filter(get_numbers, my_list) for items in check_list: print(items)

Functions vs. procedures : Differentiates between functions that return values and procedures that only print. Provides examples like def print_list(input_list): ... and def reverse_list(list_input): return list_input[::-1] .

Object‑oriented programming (OOP) : Introduces class definition, constructors, methods, and instance creation. Example class Student with add_subject and get_student_data methods, and shows importing the class from another file.

Respecting PEP‑8 : Stresses the importance of following Python style guidelines, especially snake_case naming. Provides correct and incorrect variable naming examples.

The article concludes by encouraging readers to practice these skills and provides a link to the original Medium post for further reading.