Data Structures and Strings Examples
Key Takeaway: Practice Python with 110+ runnable examples covering strings, lists, dicts, math, dates, OOP, and file I/O — complete with expected terminal outputs.
Audience & Use Case: Designed for computer science students, data analysts, backend developers, and job seekers preparing for Python technical interviews.
Quick Start & How to Use
- Select a Python example topic from the sidebar menu (or mobile dropdown).
- Examine the structured source code and corresponding expected output.
- Copy code directly or test it in our Online Python Compiler.
- Experiment by tweaking variables, loops, and conditions to deepen your understanding.
Who is this for: Beginners, interview candidates, and developers looking for reliable code snippets.
Credible Resources:Python Tutorial · Python Compiler · Python 3 Official Documentation · JavaScript Examples
Python Dictionaries
Store key-value pairs and access values.
user = {"id": 1, "name": "Sam"}
print(user["name"])
user["role"] = "admin"
print(list(user.keys()))Sam ['id', 'name', 'role']
Python Variables and Types
Define variables of different types and print them.
x = 42 name = "Alice" pi = 3.14 is_valid = True print(x, name, pi, is_valid)
42 Alice 3.14 True
Python Strings Basics
Concatenate, format, and slice strings.
s = "Hello, Python"
print(s.lower())
print(s.upper())
print(s[0:5])
print(f"Length: {len(s)}")hello, python HELLO, PYTHON Hello Length: 13
Python Lists and Loops
Iterate over lists and apply operations.
nums = [1, 2, 3, 4]
total = 0
for n in nums:
total += n
print(total)
print([n * n for n in nums])10 [1, 4, 9, 16]
Python Program to Check Whether a String is Palindrome or Not
Checks reversed equality.
s = 'madam' print(s == s[::-1])
True
Python Program to Remove Punctuations From a String
Filters punctuation.
import string
s = "Hello, world!"
print(''.join(ch for ch in s if ch not in string.punctuation))Hello world
Python Program to Sort Words in Alphabetic Order
Sorts words.
s = "banana apple cherry"
print(' '.join(sorted(s.split())))apple banana cherry
Python Program to Illustrate Different Set Operations
Union and intersection.
A = {1,2,3}
B = {3,4}
print(A | B)
print(A & B){1, 2, 3, 4}
{3}Python Program to Flatten a Nested List
Flattens nested lists.
nested = [[1,2],[3,4],[5]] flat = [x for sub in nested for x in sub] print(flat)
[1, 2, 3, 4, 5]
Python Program to Slice Lists
Demonstrates slicing.
lst = [0,1,2,3,4,5] print(lst[1:4]) print(lst[-3:])
[1, 2, 3] [3, 4, 5]
Python Program to Iterate Over Dictionaries Using for Loop
Iterates items.
d = {'a':1,'b':2}
for k, v in d.items():
print(k, v)a 1 b 2
Python Program to Sort a Dictionary by Value
Sorts by values.
d = {'a':3,'b':1,'c':2}
print(dict(sorted(d.items(), key=lambda kv: kv[1]))){'b': 1, 'c': 2, 'a': 3}Python Program to Check If a List is Empty
Truthiness check.
lst = []
print('Empty' if not lst else 'Not Empty')Empty
Python Program to Concatenate Two Lists
Uses + operator.
print([1,2] + [3,4])
[1, 2, 3, 4]
Python Program to Print Colored Text to the Terminal
ANSI escape codes.
print('\x1b[31mRed\x1b[0m')Red
Python Program to Convert String to Datetime
Uses datetime.strptime.
from datetime import datetime
dt = datetime.strptime('2025-11-14', '%Y-%m-%d')
print(dt.year, dt.month, dt.day)2025 11 14
Python Program to Get a Substring of a String
Uses slicing.
s = 'abcdef' print(s[1:4])
bcd
Python Program to Create a Long Multiline String
Triple quotes.
s = '''line1 line2 line3''' print(s)
line1 line2 line3
Python Program to Count the Number of Occurrence of a Character in String
Uses str.count.
print('banana'.count('a'))3
Python Program to Find the Square Root
Computes square root using math module.
import math print(math.sqrt(16))
4.0
Python Core Concepts & Decision Breakdown
| Category | Core Concepts | Primary Use Case | Official Docs |
|---|---|---|---|
| Primitives & Basics | int, float, str, bool | Basic arithmetic, logic checks, string formatting | Built-in Types |
| Data Structures | list, tuple, dict, set | Collections, lookup maps, data filtering | Data Structures |
| Control Flow | if/else, for, while, try/except | Iteration, conditional execution, error handling | Control Flow |
| OOP & Modular | def, class, lambda, import | Object orientation, modularization, reusability | Classes & OOP |
Keep Practicing
Use the online Python compiler to run examples and test variations. Reinforce learning by building small scripts for each topic.
Frequently Asked Questions
Learn Python by Practicing Examples
Hands-on practice is the fastest way to understand Python. Each example focuses on a single concept—from variables, strings, lists, and dictionaries to loops, functions, classes, exceptions, and file I/O. Modify examples, add new functions, and see how clean design leads to readable, maintainable code.
Use our tools to deepen learning: the Python Compiler to run snippets, the Python Official Docs for language standards, and the Python Tutorial for structured lessons.
Beginner-Friendly
Start with variables, operators, and control flow. Build confidence with small, readable programs.
Practical Patterns
Practice lists, dicts, comprehensions, functions, classes, exceptions, and file handling.
Grow Skills
Explore generators and decorators to write expressive, reusable code.